Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Engine Management Units
140 views
Skip to first unread message
Cursitor Doom
Mar 14, 2016, 7:05:23 PM3/14/16
to
Hi guys,
I have an EMU from a Land Rover which just suddenly failed one day
without warning as I was driving down the road. I was wondering if
there's any possibility of fixing it, given that schematics are AFAIK
unavailable due to commercial confidentiality. Of course there are some
basic checks that can be done without a diagram, but take a look at this
thing and tell me what I could try doing with it. I've carefully
inspected it close up but can find *nothing* at all visibly wrong with it:
http://tinyurl.com/hvk5eac
BTW, the whole board has been thickly sprayed with clear varnish which
accounts for all the bright dots which appear on some of the parts -
they're not indicative of any failure.
Any suggestions?
I have an EMU from a Land Rover which just suddenly failed one day
without warning as I was driving down the road. I was wondering if
there's any possibility of fixing it, given that schematics are AFAIK
unavailable due to commercial confidentiality. Of course there are some
basic checks that can be done without a diagram, but take a look at this
thing and tell me what I could try doing with it. I've carefully
inspected it close up but can find *nothing* at all visibly wrong with it:
http://tinyurl.com/hvk5eac
BTW, the whole board has been thickly sprayed with clear varnish which
accounts for all the bright dots which appear on some of the parts -
they're not indicative of any failure.
Any suggestions?
Clifford Heath
Mar 14, 2016, 7:11:42 PM3/14/16
to
Sjouke Burry
Mar 14, 2016, 7:24:05 PM3/14/16
to
B:Or get a magnifier glass and start searching for
damage/discoloration.
And check big caps and big transistors.
If no success, try solution A.
Or let repair shop handle it.
Cursitor Doom
Mar 14, 2016, 7:42:17 PM3/14/16
to
On Tue, 15 Mar 2016 00:24:02 +0100, Sjouke Burry wrote:
> A:try to get a replacement from a car wreckers shop.
> B:Or get a magnifier glass and start searching for damage/discoloration.
> And check big caps and big transistors.
> If no success, try solution A.
> Or let repair shop handle it.
It's up and running again with an exchange unit, but it ran smoother,
> A:try to get a replacement from a car wreckers shop.
> B:Or get a magnifier glass and start searching for damage/discoloration.
> And check big caps and big transistors.
> If no success, try solution A.
> Or let repair shop handle it.
quieter and started up quicker with the old unit that failed, so I'd like
to get the old one working again if at all possible.
Clifford Heath
Mar 14, 2016, 7:47:12 PM3/14/16
to
You'll probably find it runs just as well as the old one after
a tank or two of gas.
M Philbrook
Mar 14, 2016, 7:47:20 PM3/14/16
to
In article <56e744db$0$41576$b1db1813$1459...@news.astraweb.com>,
no....@please.net says...
I have fixed a couple of ECM's and in both cases the Xstal failed
due to mechanical vibration. Power it up using basic shop electrical
prints to the unit and find that the Xstal not operating.
Another one I did was intermitting in some function and popping up
codes randomly. I replaced a couple of caps, fixed..
The coating is tricky to get off without damage.
Jamie
no....@please.net says...
due to mechanical vibration. Power it up using basic shop electrical
prints to the unit and find that the Xstal not operating.
Another one I did was intermitting in some function and popping up
codes randomly. I replaced a couple of caps, fixed..
The coating is tricky to get off without damage.
Jamie
M Philbrook
Mar 14, 2016, 7:53:43 PM3/14/16
to
In article <nc7i2r$ui0$2...@dont-email.me>, cu...@notformail.com says...
That will fix itself.
The same is true if you disconnected the battery for a while
with the other one.
The same is true if you disconnected the battery for a while
with the other one.
Cursitor Doom
Mar 15, 2016, 7:08:34 AM3/15/16
to
On Mon, 14 Mar 2016 19:58:50 -0500, M Philbrook wrote:
> That will fix itself.
>
> The same is true if you disconnected the battery for a while with the
> other one.
I wish. It's been replaced for over 9 months now and it's still the same
> That will fix itself.
>
> The same is true if you disconnected the battery for a while with the
> other one.
as the day it was fitted.
But this is really about trying to rescue the old one. They don't come
cheap!
pf...@aol.com
Mar 15, 2016, 9:21:33 AM3/15/16
to
On Tuesday, March 15, 2016 at 7:08:34 AM UTC-4, Cursitor Doom wrote:
> I wish. It's been replaced for over 9 months now and it's still the same
> as the day it was fitted.
> But this is really about trying to rescue the old one. They don't come
> cheap!
Try this:
> I wish. It's been replaced for over 9 months now and it's still the same
> as the day it was fitted.
> But this is really about trying to rescue the old one. They don't come
> cheap!
Re-install the new unit. Power up the electrical system, but DO NOT start the engine.
Here is the tricky part and be exceedingly careful: While powered up, disconnect the battery, NEGATIVE FIRST. Make sure when that clamp comes off the battery it does so cleanly and quickly. SHORT the positive clamp to the negative clamp immediately and hold for a minimum of 30 seconds. This is the functional equivalent of rebooting the ECU. Shut off the electrical system. Reinstall the battery. Attempt to start. Does this help?
Note: If you have any coded devices such as so-called 'infotainment' systems and such, you will have to re-code them. If you have a chip-based navigation system, remove the chip for this process. But, 3 times in 10, it works. Not bad odds if the alternative is landfill.
If you have a Bosch unit, this is far more likely to work than if you have a British-made unit.... getting back to that old joke: why do the British drink warm beer?
Peter Wieck
Melrose Park, PA
legg
Mar 15, 2016, 9:58:45 AM3/15/16
to
Have you mentioned this to the technicians who made the change?
RL
Cursitor Doom
Mar 15, 2016, 10:06:53 AM3/15/16
to
On Tue, 15 Mar 2016 06:21:27 -0700, pf...@aol.com wrote:
> On Tuesday, March 15, 2016 at 7:08:34 AM UTC-4, Cursitor Doom wrote:
>
>> I wish. It's been replaced for over 9 months now and it's still the
>> same as the day it was fitted.
>> But this is really about trying to rescue the old one. They don't come
>> cheap!
>
> Try this:
>
> Re-install the new unit. Power up the electrical system, but DO NOT
> start the engine.
>
> Here is the tricky part and be exceedingly careful: While powered up,
> disconnect the battery, NEGATIVE FIRST. Make sure when that clamp comes
> off the battery it does so cleanly and quickly. SHORT the positive clamp
> to the negative clamp immediately and hold for a minimum of 30 seconds.
> This is the functional equivalent of rebooting the ECU. Shut off the
> electrical system. Reinstall the battery. Attempt to start. Does this
> help?
We're getting completely off topic in being distracted by the new EMU,
> On Tuesday, March 15, 2016 at 7:08:34 AM UTC-4, Cursitor Doom wrote:
>
>> I wish. It's been replaced for over 9 months now and it's still the
>> same as the day it was fitted.
>> But this is really about trying to rescue the old one. They don't come
>> cheap!
>
> Try this:
>
> Re-install the new unit. Power up the electrical system, but DO NOT
> start the engine.
>
> Here is the tricky part and be exceedingly careful: While powered up,
> disconnect the battery, NEGATIVE FIRST. Make sure when that clamp comes
> off the battery it does so cleanly and quickly. SHORT the positive clamp
> to the negative clamp immediately and hold for a minimum of 30 seconds.
> This is the functional equivalent of rebooting the ECU. Shut off the
> electrical system. Reinstall the battery. Attempt to start. Does this
> help?
but I'll just answer this point. Every time I leave that vehicle for a
few days, I'll isolate the battery, anyway. So it has been repeatedly
"rebooted" dozens of times since the old one was replaced.
BUT my question is NOT about the new one; it's about how easily the old
ONE can be fixed without schematics (M. Philbrook, many thanks I'll try
your suggestion re xtal).
Cursitor Doom
Mar 15, 2016, 10:07:55 AM3/15/16
to
On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
> <cu...@notformail.com> wrote:
>
>>But this is really about trying to rescue the old one. They don't come
>>cheap!
>
> The issue is with the new part, not the old one.
Wrong! The question *solely* concerns the *old* unit that failed.
> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
> <cu...@notformail.com> wrote:
>
>>But this is really about trying to rescue the old one. They don't come
>>cheap!
>
> The issue is with the new part, not the old one.
pf...@aol.com
Mar 15, 2016, 11:24:29 AM3/15/16
to
legg
Mar 15, 2016, 2:26:22 PM3/15/16
to
On Tue, 15 Mar 2016 14:04:46 -0000 (UTC), Cursitor Doom
You're not in a position to resurrect the old ECU.
RL
<cu...@notformail.com> wrote:
>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>
>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>> <cu...@notformail.com> wrote:
>>
>>>But this is really about trying to rescue the old one. They don't come
>>>cheap!
>>
>> The issue is with the new part, not the old one.
>
>Wrong! The question *solely* concerns the *old* unit that failed.
The issue is your dissatisfaction with the repaired automobile.
>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>
>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>> <cu...@notformail.com> wrote:
>>
>>>But this is really about trying to rescue the old one. They don't come
>>>cheap!
>>
>> The issue is with the new part, not the old one.
>
>Wrong! The question *solely* concerns the *old* unit that failed.
You're not in a position to resurrect the old ECU.
RL
DaveC
Mar 15, 2016, 2:49:04 PM3/15/16
to
On 15 Mar 2016, Cursitor Doom wrote
(in article <nc94pu$on1$6...@dont-email.me>):
> Wrong! The question *solely* concerns the *old* unit that failed.
Welcome to USENET. There is no “on-topic”!
Under conformal coating it is difficult to examine anything.
Check any large transistors.
I’d also look for broken solder joints on the large devices (caps,
transformer, choke, I/O connectors). Also look closely at the cap “north”
of the big choke. Has it leaked and damaged a trace?
Also check ESR of all the electro caps.
And as was mentioned earlier, be sure the xtal is working.
A success story:
https://www.youtube.com/watch?v=uLIHxqqrY_M
Good luck!
(in article <nc94pu$on1$6...@dont-email.me>):
> Wrong! The question *solely* concerns the *old* unit that failed.
Under conformal coating it is difficult to examine anything.
Check any large transistors.
I’d also look for broken solder joints on the large devices (caps,
transformer, choke, I/O connectors). Also look closely at the cap “north”
of the big choke. Has it leaked and damaged a trace?
Also check ESR of all the electro caps.
And as was mentioned earlier, be sure the xtal is working.
A success story:
https://www.youtube.com/watch?v=uLIHxqqrY_M
Good luck!
DaveC
Mar 15, 2016, 3:09:57 PM3/15/16
to
If all else looks good, a winding in that transformer might be open. Remove
and “ring” it.
and “ring” it.
Cursitor Doom
Mar 15, 2016, 4:05:04 PM3/15/16
to
question was about the OLD one (at the risk of repeating myself).
Jon Elson
Mar 15, 2016, 5:52:42 PM3/15/16
to
something like what they used to do? If it appeas totally dead, there's a
possibility that a voltage regulator or other power switching circuit has
failed. Looks like it has a switching power supply, that will make things a
little harder. Yeah, the conformal coating is really necessary in
automotive gear, but makes rework tough.
Also, check all connectors and other large parts soldered to the board,
breaks in the solder joints are supposed to be a very common cause of
failure.
Jon
legg
Mar 15, 2016, 8:00:38 PM3/15/16
to
On Tue, 15 Mar 2016 20:01:54 -0000 (UTC), Cursitor Doom
Looking at what you've offered, you might re-examine locally:
http://www.magma.ca/~legg/TVS/EMU_captive_detritus.jpg
http://www.magma.ca/~legg/TVS/EMU_green_reflection.jpg
http://www.magma.ca/~legg/TVS/EMU_red_reflection.jpg
http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant.jpg
http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant_2.jpg
I expect these are mostly reflections in the protective epoxy, or
flow/tension marks formed in its application, but could be signs of
contamination or damage.
Even checking point to point contact is a trial with this stuff.
Vibration produces intermittent faults on assemblies (where the parts
don't actually shear off completely) The most suspect parts are those
with mechanical attributes - the crystal as previously suggested, the
connectors and bulky components. Reflowing the SJ of the latter might
be informative - any uncharacteristic loosness in the soldered
material of the melted joint is a giveaway.
As previous - an intermittent fault is unlikely to result in repeated
DOA symptoms, but it can be recorded for posterity in the firmware,
with DOA symptoms, or break small-signal paths with the same effect.
Did you try a reset on the 'dead' unit, before replacing it?
The fact that its replacement didn't involve the surrender of the
defect unit (for a discount in pricing) is a signal from the mfr
regarding their view on the viability of repair. They are in the most
sensible position to do so, after-warranty.
RL
<cu...@notformail.com> wrote:
>On Tue, 15 Mar 2016 14:25:41 -0500, legg wrote:
>
>> On Tue, 15 Mar 2016 14:04:46 -0000 (UTC), Cursitor Doom
>> <cu...@notformail.com> wrote:
>>
>>>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>>>
>>>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>>>> <cu...@notformail.com> wrote:
>>>>
>>>>>But this is really about trying to rescue the old one. They don't come
>>>>>cheap!
>>>>
>>>> The issue is with the new part, not the old one.
>>>
>>>Wrong! The question *solely* concerns the *old* unit that failed.
>>
>> The issue is your dissatisfaction with the repaired automobile.
>>
>> You're not in a position to resurrect the old ECU.
>
>The new ECU in all probability just requires a software tweak. My
>question was about the OLD one (at the risk of repeating myself).
There's not much you can tell from a photograph of limited resolution.
>On Tue, 15 Mar 2016 14:25:41 -0500, legg wrote:
>
>> On Tue, 15 Mar 2016 14:04:46 -0000 (UTC), Cursitor Doom
>> <cu...@notformail.com> wrote:
>>
>>>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>>>
>>>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>>>> <cu...@notformail.com> wrote:
>>>>
>>>>>But this is really about trying to rescue the old one. They don't come
>>>>>cheap!
>>>>
>>>> The issue is with the new part, not the old one.
>>>
>>>Wrong! The question *solely* concerns the *old* unit that failed.
>>
>> The issue is your dissatisfaction with the repaired automobile.
>>
>> You're not in a position to resurrect the old ECU.
>
>The new ECU in all probability just requires a software tweak. My
>question was about the OLD one (at the risk of repeating myself).
Looking at what you've offered, you might re-examine locally:
http://www.magma.ca/~legg/TVS/EMU_captive_detritus.jpg
http://www.magma.ca/~legg/TVS/EMU_green_reflection.jpg
http://www.magma.ca/~legg/TVS/EMU_red_reflection.jpg
http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant.jpg
http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant_2.jpg
I expect these are mostly reflections in the protective epoxy, or
flow/tension marks formed in its application, but could be signs of
contamination or damage.
Even checking point to point contact is a trial with this stuff.
Vibration produces intermittent faults on assemblies (where the parts
don't actually shear off completely) The most suspect parts are those
with mechanical attributes - the crystal as previously suggested, the
connectors and bulky components. Reflowing the SJ of the latter might
be informative - any uncharacteristic loosness in the soldered
material of the melted joint is a giveaway.
As previous - an intermittent fault is unlikely to result in repeated
DOA symptoms, but it can be recorded for posterity in the firmware,
with DOA symptoms, or break small-signal paths with the same effect.
Did you try a reset on the 'dead' unit, before replacing it?
The fact that its replacement didn't involve the surrender of the
defect unit (for a discount in pricing) is a signal from the mfr
regarding their view on the viability of repair. They are in the most
sensible position to do so, after-warranty.
RL
DaveC
Mar 15, 2016, 8:21:13 PM3/15/16
to
Cursitor Doom
Mar 15, 2016, 8:59:44 PM3/15/16
to
On Tue, 15 Mar 2016 17:21:08 -0700, DaveC wrote:
>> http://tinyurl.com/hvk5eac
>
> Any chance of posting a super-high resolution image?
If I can figure out how to get the back off and photograph both sides,
>> http://tinyurl.com/hvk5eac
>
> Any chance of posting a super-high resolution image?
I'll do it. The blurring issue I am having is with the autofocus which is
being hijacked by the two big electrolytics. I'll have to read the
camera's FM and find out how to switch it to manual. These damn things
are so complicated nowadays. :(
Cursitor Doom
Mar 15, 2016, 9:03:32 PM3/15/16
to
have come up with). I don't think I will have sufficient time at this
stage to see this through to the end if it turns out to be tricky; I
can't face the prospect of this becoming another saga like the Philips
scope turned out to be. :(
I'll try to get the back off tomorrow...
Look165
Mar 16, 2016, 6:30:55 AM3/16/16
to
I would say the 2 electrolytic caps.
Cursitor Doom a écrit :
Cursitor Doom a écrit :
John-Del
Mar 16, 2016, 7:03:16 AM3/16/16
to
On Tuesday, March 15, 2016 at 8:59:44 PM UTC-4, Cursitor Doom wrote:
> On Tue, 15 Mar 2016 17:21:08 -0700, DaveC wrote:
>
> >> http://tinyurl.com/hvk5eac
> >
> > Any chance of posting a super-high resolution image?
>
> If I can figure out how to get the back off and photograph both sides,
> I'll do it.
There may be nothing on the back side. I repair (take a shot at) a lot of car electronics from a nearby car dealership (mostly clusters) and have seen some PCMs that are pretty much bonded to the bottom of the pan for heat sinking purposes. Nothing to see on the other side except foil damage if there was a water leak.
> On Tue, 15 Mar 2016 17:21:08 -0700, DaveC wrote:
>
> >> http://tinyurl.com/hvk5eac
> >
> > Any chance of posting a super-high resolution image?
>
> If I can figure out how to get the back off and photograph both sides,
> I'll do it.
Never been in a Rover PCM.
Cursitor Doom
Mar 16, 2016, 7:12:52 AM3/16/16
to
On Wed, 16 Mar 2016 11:30:49 +0100, Look165 wrote:
> I would say the 2 electrolytic caps.
I've heard that's a common failure point with these units, but all the
> I would say the 2 electrolytic caps.
electros have checked out fine on this particular one.
Look165
Mar 16, 2016, 10:28:09 AM3/16/16
to
Check them instead of usisng random statistics.
Cursitor Doom a écrit :
Cursitor Doom a écrit :
DaveC
Mar 16, 2016, 12:42:33 PM3/16/16
to
On 16 Mar 2016, Cursitor Doom wrote
(in article <ncbetl$tfi$1...@dont-email.me>):
> > I would say the 2 electrolytic caps.
>
> I've heard that's a common failure point with these units, but all the
> electros have checked out fine on this particular one.
“checked out fine...” means you tested what? Capacitance? ESR?
In-circuit? Removed?
Details!
(in article <ncbetl$tfi$1...@dont-email.me>):
> > I would say the 2 electrolytic caps.
>
> I've heard that's a common failure point with these units, but all the
> electros have checked out fine on this particular one.
In-circuit? Removed?
Details!
Cursitor Doom
Mar 16, 2016, 2:19:57 PM3/16/16
to
On Wed, 16 Mar 2016 09:42:30 -0700, DaveC wrote:
> “checked out fine...” means you tested what? Capacitance? ESR?
> In-circuit? Removed?
>
> Details!
The ESRs were slightly high (in circuit) but not enough to cause sudden
> “checked out fine...” means you tested what? Capacitance? ESR?
> In-circuit? Removed?
>
> Details!
total failure. But they appear to be easily removeable so I'll take them
out and check them independently.
I should repeat I don't have the time right now to go down every avenue
if this turns out to be more than a simple fix; I'm really just trying to
establish whether the thing is salvageable at all. However, I am noting
down all the suggestions made here for future reference for when I do
have time.
DaveC
Mar 16, 2016, 2:45:08 PM3/16/16
to
> “checked out fine...” means you tested what? Capacitance? ESR?
> In-circuit? Removed?
Visually?
> In-circuit? Removed?
Cursitor Doom
Mar 16, 2016, 3:39:26 PM3/16/16
to
I was just taking a closer look at the board a moment ago under a glass
and spotted something that requires further investigation. Going to have
to get my stereoscope out of storage for this one. Tiny clusters of what
look like *very* fine gauge enamel copper wire clearly bridging across
vias in various points around the board and obviously not *supposed* to
be there. If they turn out to be conductive, I could be in business!
Don't want to get my hopes up on this one, though. Probably just a false
alarm but *definitely* requiring closer examination with something more
powerful than a glass....
Turns out to get the caps out of circuit requires a 6mm ring spanner
which I shall have to procure from a local emporium tomorrow when they re-
open. Fortunately I already have a 13mm one for the other ends.
DaveC
Mar 16, 2016, 4:00:22 PM3/16/16
to
> Turns out to get the caps out of circuit requires a 6mm ring spanner
> which I shall have to procure from a local emporium tomorrow when they re-
> open. Fortunately I already have a 13mm one for the other ends.
Try 1/4”. That’s 6.35mm. Might work...
> which I shall have to procure from a local emporium tomorrow when they re-
> open. Fortunately I already have a 13mm one for the other ends.
Cursitor Doom
Mar 16, 2016, 4:26:51 PM3/16/16
to
good in this case) in either metric or imperial, I'm afraid. It won't
kill me to buy one the correct size tomorrow.
Cursitor Doom
Mar 16, 2016, 7:24:54 PM3/16/16
to
On Tue, 15 Mar 2016 19:59:53 -0500, legg wrote:
> On Tue, 15 Mar 2016 20:01:54 -0000 (UTC), Cursitor Doom
> <cu...@notformail.com> wrote:
>
>>On Tue, 15 Mar 2016 14:25:41 -0500, legg wrote:
>>
>>> On Tue, 15 Mar 2016 14:04:46 -0000 (UTC), Cursitor Doom
>>> <cu...@notformail.com> wrote:
>>>
>>>>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>>>>
>>>>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>>>>> <cu...@notformail.com> wrote:
>>>>>
>>>>>>But this is really about trying to rescue the old one. They don't
>>>>>>come cheap!
>>>>>
>>>>> The issue is with the new part, not the old one.
>>>>
>>>>Wrong! The question *solely* concerns the *old* unit that failed.
>>>
>>> The issue is your dissatisfaction with the repaired automobile.
>>>
>>> You're not in a position to resurrect the old ECU.
>>
>>The new ECU in all probability just requires a software tweak. My
>>question was about the OLD one (at the risk of repeating myself).
>
> There's not much you can tell from a photograph of limited resolution.
> Looking at what you've offered, you might re-examine locally:
>
> http://www.magma.ca/~legg/TVS/EMU_captive_detritus.jpg
> http://www.magma.ca/~legg/TVS/EMU_green_reflection.jpg
> http://www.magma.ca/~legg/TVS/EMU_red_reflection.jpg
> http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant.jpg
> http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant_2.jpg
I don't know how the hell you were able to spot those markings from the
> On Tue, 15 Mar 2016 20:01:54 -0000 (UTC), Cursitor Doom
> <cu...@notformail.com> wrote:
>
>>On Tue, 15 Mar 2016 14:25:41 -0500, legg wrote:
>>
>>> On Tue, 15 Mar 2016 14:04:46 -0000 (UTC), Cursitor Doom
>>> <cu...@notformail.com> wrote:
>>>
>>>>On Tue, 15 Mar 2016 09:58:03 -0500, legg wrote:
>>>>
>>>>> On Tue, 15 Mar 2016 11:05:24 -0000 (UTC), Cursitor Doom
>>>>> <cu...@notformail.com> wrote:
>>>>>
>>>>>>But this is really about trying to rescue the old one. They don't
>>>>>>come cheap!
>>>>>
>>>>> The issue is with the new part, not the old one.
>>>>
>>>>Wrong! The question *solely* concerns the *old* unit that failed.
>>>
>>> The issue is your dissatisfaction with the repaired automobile.
>>>
>>> You're not in a position to resurrect the old ECU.
>>
>>The new ECU in all probability just requires a software tweak. My
>>question was about the OLD one (at the risk of repeating myself).
>
> There's not much you can tell from a photograph of limited resolution.
> Looking at what you've offered, you might re-examine locally:
>
> http://www.magma.ca/~legg/TVS/EMU_captive_detritus.jpg
> http://www.magma.ca/~legg/TVS/EMU_green_reflection.jpg
> http://www.magma.ca/~legg/TVS/EMU_red_reflection.jpg
> http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant.jpg
> http://www.magma.ca/~legg/TVS/EMU_soluble_contaminant_2.jpg
poor detail in the photo. The last two details you posted show the
extremely fine enamel copper wire-looking debris which crops up in other
places on the board and across vias and traces. If this debris conducts,
it could easily be the cause of the problem. I have to hoist my
stereoscope out of storage and take a better look tomorrow. Well spotted
indeed. Remarkable!
As for the other bits you found, I'll investigate them at the same time
when my stereoscope is set up.
Jon Elson
Mar 16, 2016, 9:51:48 PM3/16/16
to
Cursitor Doom wrote:
> On Wed, 16 Mar 2016 11:45:04 -0700, DaveC wrote:
>
>>> “checked out fine...” means you tested what? Capacitance? ESR?
>>> In-circuit? Removed?
>>
>> Visually?
>
> No signs of bulging or seepage.
>
> I was just taking a closer look at the board a moment ago under a glass
> and spotted something that requires further investigation. Going to have
> to get my stereoscope out of storage for this one. Tiny clusters of what
> look like *very* fine gauge enamel copper wire clearly bridging across
> vias in various points around the board and obviously not *supposed* to
> be there.
Woo Hoo! Sounds like tin whiskers! The conformal coat is "SUPPOSED" to
> On Wed, 16 Mar 2016 11:45:04 -0700, DaveC wrote:
>
>>> “checked out fine...” means you tested what? Capacitance? ESR?
>>> In-circuit? Removed?
>>
>> Visually?
>
> No signs of bulging or seepage.
>
> I was just taking a closer look at the board a moment ago under a glass
> and spotted something that requires further investigation. Going to have
> to get my stereoscope out of storage for this one. Tiny clusters of what
> look like *very* fine gauge enamel copper wire clearly bridging across
> vias in various points around the board and obviously not *supposed* to
> be there.
suppress the whisker growth, but there are quite a few reports that the
whiskers just poke through the coating, they ARE real sharp.
Jon
legg
Mar 16, 2016, 10:51:03 PM3/16/16
to
On Wed, 16 Mar 2016 23:21:41 -0000 (UTC), Cursitor Doom
Looked to me more like dye concentrating as the curing epoxy puckered.
Did you ever reset this thing, while it was still in the vehicle?
RL
Did you ever reset this thing, while it was still in the vehicle?
RL
Cursitor Doom
Mar 17, 2016, 6:12:03 AM3/17/16
to
On Wed, 16 Mar 2016 22:50:06 -0500, legg wrote:
> Looked to me more like dye concentrating as the curing epoxy puckered.
So not likely to cause a fault then?
> Looked to me more like dye concentrating as the curing epoxy puckered.
> Did you ever reset this thing, while it was still in the vehicle?
swapped the unit over wouldn't have gone to the trouble of sourcing a
replacement. They charged me next to nothing for the job so I trust them.
Cursitor Doom
Mar 17, 2016, 6:19:30 AM3/17/16
to
that:
1. TW growth happened solely inside chips and so was normally invisible.
2. tin whiskers were invariably silver in colour.
These I have here are like the old kind of enamel copper wire. Nowadays
all enamel copper seems to be clear, but back in the day the enamel was a
sort of deep plum shade - which is what I see here. I'll do some searches
for pictures of TW and see if some match what I see on this board....
Look165
Mar 17, 2016, 7:07:57 AM3/17/16
to
I wonnder how you can determine an ESR visually !
And technically, it's not so easy to measure this parameter.
Cursitor Doom a écrit :
And technically, it's not so easy to measure this parameter.
Cursitor Doom a écrit :
legg
Mar 17, 2016, 8:05:24 AM3/17/16
to
On Thu, 17 Mar 2016 10:08:49 -0000 (UTC), Cursitor Doom
<cu...@notformail.com> wrote:
>On Wed, 16 Mar 2016 22:50:06 -0500, legg wrote:
>
>> Looked to me more like dye concentrating as the curing epoxy puckered.
>
>So not likely to cause a fault then?
Must have been pretty strong stuff, to strip colour out of the mask,
<cu...@notformail.com> wrote:
>On Wed, 16 Mar 2016 22:50:06 -0500, legg wrote:
>
>> Looked to me more like dye concentrating as the curing epoxy puckered.
>
>So not likely to cause a fault then?
but no, not a conductive path.
>
>> Did you ever reset this thing, while it was still in the vehicle?
>
>No. I think if the fix were that simple the service specialists who
>swapped the unit over wouldn't have gone to the trouble of sourcing a
>replacement. They charged me next to nothing for the job so I trust them.
?? Just charged you for the ECU, that they happened to have lying
>> Did you ever reset this thing, while it was still in the vehicle?
>
>No. I think if the fix were that simple the service specialists who
>swapped the unit over wouldn't have gone to the trouble of sourcing a
>replacement. They charged me next to nothing for the job so I trust them.
around? Very obliging...
If you trusted them from past work, that's another thing entirely.
RL
MJC
Mar 17, 2016, 9:01:42 AM3/17/16
to
In article <nce05k$n7j$2...@dont-email.me>, cu...@notformail.com says...
confusion! Even if all enamel is now also the sort that turns into flux
if you try to solder the wire...
Mike.
>
> Nowadays
> all enamel copper seems to be clear, but back in the day the enamel was a
> sort of deep plum shade - which is what I see here. I'll do some searches
> for pictures of TW and see if some match what I see on this board....
I didn't know modern enamel had gone clear. Sounds like a recipe for
> Nowadays
> all enamel copper seems to be clear, but back in the day the enamel was a
> sort of deep plum shade - which is what I see here. I'll do some searches
> for pictures of TW and see if some match what I see on this board....
confusion! Even if all enamel is now also the sort that turns into flux
if you try to solder the wire...
Mike.
Cursitor Doom
Mar 17, 2016, 11:45:00 AM3/17/16
to
On Thu, 17 Mar 2016 08:04:41 -0500, legg wrote:
> ?? Just charged you for the ECU, that they happened to have lying
> around? Very obliging...
It wasn't a stock item. They had to order it in and it took about 10 days
> ?? Just charged you for the ECU, that they happened to have lying
> around? Very obliging...
in all. I'm normally suspicious, but not on this one.
Cursitor Doom
Mar 17, 2016, 11:49:25 AM3/17/16
to
On Thu, 17 Mar 2016 13:01:37 +0000, MJC wrote:
> I didn't know modern enamel had gone clear. Sounds like a recipe for
> confusion! Even if all enamel is now also the sort that turns into flux
> if you try to solder the wire...
>
> Mike.
Sorry, no idea what you're getting at here.
> I didn't know modern enamel had gone clear. Sounds like a recipe for
> confusion! Even if all enamel is now also the sort that turns into flux
> if you try to solder the wire...
>
> Mike.
Cursitor Doom
Mar 17, 2016, 1:27:13 PM3/17/16
to
I can't find any pictures that resemble these things on the web.
Following a closer look with a stereoscope, there are outbreaks of these
growths in at *least* a dozen places on this board. Here's two more
sharper pictures with the problem areas outlined:
https://www.flickr.com/photos/128859641@N02/25236055623/in/dateposted-
public/
https://www.flickr.com/photos/128859641@N02/25836586336/in/dateposted-
public/
All the pictures I've seen on the net show whiskers as silver in colour
but these are dark, metallic plum. They typically spring from vias in a
kind of branching, fern-like formation and certainly reach out to touch
other traces on the board.
Anyone seen anything like this before? Ideas on how to proceed?
DaveC
Mar 17, 2016, 1:56:42 PM3/17/16
to
> All the pictures I've seen on the net show whiskers as silver in colour
> but these are dark, metallic plum. They typically spring from vias in a
> kind of branching, fern-like formation and certainly reach out to touch
> other traces on the board.
Cracks?
> but these are dark, metallic plum. They typically spring from vias in a
> kind of branching, fern-like formation and certainly reach out to touch
> other traces on the board.
> Anyone seen anything like this before? Ideas on how to proceed?
Choose one of these, try acetone on a Q-tip cotton ear bud to dissolve the
coating (try to not disturb the “thing” that lies below the coating--if,
in fact it is below the coating). Get a “burnishing brush” with
fiberglass bristles (used to clean oxidation from copper, etc.) and start
gently rubbing the site. I think you’ll quickly discover if it’s a
surface growth, or a crack or other phenomenon.
Good luck.
Cursitor Doom
Mar 17, 2016, 2:04:09 PM3/17/16
to
On Thu, 17 Mar 2016 10:56:37 -0700, DaveC wrote:
> Choose one of these, try acetone on a Q-tip cotton ear bud to dissolve
> the coating (try to not disturb the “thing” that lies below the
> coating--if,
> in fact it is below the coating). Get a “burnishing brush” with
> fiberglass bristles (used to clean oxidation from copper, etc.) and
> start gently rubbing the site. I think you’ll quickly discover if it’s a
> surface growth, or a crack or other phenomenon.
>
> Good luck.
Thanks. They're definitely not cracks, they're fibres of some sort.
> Choose one of these, try acetone on a Q-tip cotton ear bud to dissolve
> the coating (try to not disturb the “thing” that lies below the
> coating--if,
> in fact it is below the coating). Get a “burnishing brush” with
> fiberglass bristles (used to clean oxidation from copper, etc.) and
> start gently rubbing the site. I think you’ll quickly discover if it’s a
> surface growth, or a crack or other phenomenon.
>
> Good luck.
Look165
Mar 17, 2016, 2:57:14 PM3/17/16
to
This type of caps is known for drying inside with time.
Cursitor Doom
Mar 17, 2016, 3:04:03 PM3/17/16
to
On Thu, 17 Mar 2016 19:57:11 +0100, Look165 wrote:
> This type of caps is known for drying inside with time.
Yes, I know. But these are not faulty. I tested them with one of these
> This type of caps is known for drying inside with time.
meters:
http://www.peakelec.co.uk/acatalog/jz_esr70.html
Current most likely possibility is shorting between PCB traces due to
growths of some kind:
https://www.flickr.com/photos/128859641@N02/25836586336/in/dateposted-
public/
Jon Elson
Mar 17, 2016, 5:26:20 PM3/17/16
to
Cursitor Doom wrote:
>
> Thank you, Jon. An interesting suggestion! But I was under the impression
> that:
>
> 1. TW growth happened solely inside chips and so was normally invisible.
>
Absolutely not! I had some Xilinx chips where the leadframe was tinned
>
> Thank you, Jon. An interesting suggestion! But I was under the impression
> that:
>
> 1. TW growth happened solely inside chips and so was normally invisible.
>
before the IC was mounted and encapsulated, then the leads were bent. This
put strain into the tin plating, and whiskers grew from that. Xilinx'
solution was to REALLY FRY the chips when reflowing the board, which I did
not think highly of! They seem to have changed their plating to reduce the
whisker growth. These were easily seen with a microscope, and were clearly
sprouting out of the leads RIGHT at the bends.
Lots of reports indicate tin whiskers on circuit boards, connectors, IC
leads, etc. Moisture exposure seems to be an important part of the
conditions where they grow.
> 2. tin whiskers were invariably silver in colour.
VARIETY of colors. Most of these I'm more accustomed to see where the Tin
has been heated (as when soldering) but I have definitely seen Tin turn all
shades of purple. Also, the conformal coating may have chemicals that
caused the tin whiskers to change color.
>
> These I have here are like the old kind of enamel copper wire. Nowadays
> all enamel copper seems to be clear, but back in the day the enamel was a
> sort of deep plum shade - which is what I see here. I'll do some searches
> for pictures of TW and see if some match what I see on this board....
Tin can definitely turn this "plum" shade.
> These I have here are like the old kind of enamel copper wire. Nowadays
> all enamel copper seems to be clear, but back in the day the enamel was a
> sort of deep plum shade - which is what I see here. I'll do some searches
> for pictures of TW and see if some match what I see on this board....
Jon
Jon Elson
Mar 17, 2016, 5:33:21 PM3/17/16
to
could be some sort of conductive stuff that has grown between nets on the
board. One possibility is they are fibers from a brush that either cleaned
the board or applied the conformal coat. But, they could still be trouble,
maybe they start out non-conductive but become conductive when moisture is
absorbed. Since you say the sprout from vias, maybe the board had some
contaminant left in the vias that slowly creeps out under heat and
electrical field. Anyway, not much to lose by trying to remove the
conformal coat at these spots and see if the EMU comes back to life.
If it does, then you need to get some new conformal coat and re-seal those
spots.
Jon
jurb...@gmail.com
Mar 17, 2016, 6:26:03 PM3/17/16
to
>" wonnder how you can determine an ESR visually !
>
>And technically, it's not so easy to measure this parameter. "
With a square wave that has a fast enough slew rate for the vertical parts of the scope trace to disappear. The square wave comes from a known impedance and is high enough frequency so Xc is minimal. Measure the amplitude of the parts you can't see and then it is simple ohm's law.
>
>And technically, it's not so easy to measure this parameter. "
I use 400 mV 1,000 Hz with a 360 ohm impedance which does not make the numbers easy but it makes for quick troubleshooting.
Cursitor Doom
Mar 17, 2016, 6:43:32 PM3/17/16
to
On Thu, 17 Mar 2016 16:26:54 -0500, Jon Elson wrote:
> Tin can definitely turn this "plum" shade.
>
> Jon
In that case I wonder how I would go about measuring the resistance of
> Tin can definitely turn this "plum" shade.
>
> Jon
these things? Maybe I could lift one off with a piece of sticky tape if
they're not too fragile. Can't think of a better way!
legg
Mar 17, 2016, 7:26:35 PM3/17/16
to
On Thu, 17 Mar 2016 19:00:52 -0000 (UTC), Cursitor Doom
<cu...@notformail.com> wrote:
>https://www.flickr.com/photos/128859641@N02/25836586336/in/dateposted-
>public/
You're going to have to get more localized images of individual sites,
using a minimum x10 magnification, and enhanced/varying side-lighting.
A 'star' group, or part group should occupy a full image. Manual
marking should not interfere and should use line widths <<smaller than
the image details themselves.
If possible, you should label or datestamp each individually for
reference.
The captive metalic detritus on the body of one resistor did not
resolve any better in the later image. If possible, angled images can
be informative, when monocular, and diffused lighting will reduce
glare.
If you do post more detailed images to the same flikr thread, they can
be downloaded and examined by IPC Technet group members, with comments
at
http://listserv.ipc.org/scripts/wa.exe?A1=ind1603&L=TechNet
RL
<cu...@notformail.com> wrote:
>https://www.flickr.com/photos/128859641@N02/25836586336/in/dateposted-
>public/
You're going to have to get more localized images of individual sites,
using a minimum x10 magnification, and enhanced/varying side-lighting.
A 'star' group, or part group should occupy a full image. Manual
marking should not interfere and should use line widths <<smaller than
the image details themselves.
If possible, you should label or datestamp each individually for
reference.
The captive metalic detritus on the body of one resistor did not
resolve any better in the later image. If possible, angled images can
be informative, when monocular, and diffused lighting will reduce
glare.
If you do post more detailed images to the same flikr thread, they can
be downloaded and examined by IPC Technet group members, with comments
at
http://listserv.ipc.org/scripts/wa.exe?A1=ind1603&L=TechNet
RL
Cursitor Doom
Mar 17, 2016, 7:37:16 PM3/17/16
to
from the stereoscope which is just in its own class for this kind of
thing and shows *so* much more detail, but I don't have a suitable
adaptor. I'll check out your link tomorrow as it's getting very late here
now...
Jon Elson
Mar 17, 2016, 10:36:30 PM3/17/16
to
could still be trouble after years of exposure to <something>.
Are these on top of the conformal coat or underneath/within it? If they are
in the coat, then it will be hard to extract them.
Jon
legg
Mar 18, 2016, 12:07:50 AM3/18/16
to
would require SEM EDX to confirm. This contamination could difuse in
the conformal coating cure stress lines (ie the pucker).
I don't see vias involved in every instance - some sites seem to
develop at pure surface mount pad sites.
There's an image of copper dendrites on Steve Zeva's gallery
http://stevezeva.homestead.com/
http://stevezeva.homestead.com/Dendrite_1.jpg
These tend to be inter-node rather than centrally expanding.
A close examination of tin whiskers should reveal a characteristic
three dimensional spike/thread detail. Not likely here.
RL
Cursitor Doom
Mar 18, 2016, 4:39:29 AM3/18/16
to
On Thu, 17 Mar 2016 21:36:17 -0500, Jon Elson wrote:
They seem to emerge from under it and spread along the surface, but I
can't confirm that yet as I've resisted disturbing them so far in case
they disintegrate and defy further analysis.
It's a good question, though, and I expect to be able to report back on
this later today. I'll sacrifice one of the patches and find out.
They seem to emerge from under it and spread along the surface, but I
can't confirm that yet as I've resisted disturbing them so far in case
they disintegrate and defy further analysis.
It's a good question, though, and I expect to be able to report back on
this later today. I'll sacrifice one of the patches and find out.
Cursitor Doom
Mar 18, 2016, 4:54:27 AM3/18/16
to
On Fri, 18 Mar 2016 00:07:03 -0500, legg wrote:
> Early technet response suggests chemical contamination in vias, but
> would require SEM EDX to confirm. This contamination could difuse in the
> conformal coating cure stress lines (ie the pucker).
Can you post a url for this site? I searched but got about a million
> Early technet response suggests chemical contamination in vias, but
> would require SEM EDX to confirm. This contamination could difuse in the
> conformal coating cure stress lines (ie the pucker).
microsoft support links instead.
"SEM EDX"? Is that something to do with electron microscopy? I have an
admittedly huge collection of test gear here, but not a single electron
microscope.
> I don't see vias involved in every instance - some sites seem to develop
> at pure surface mount pad sites.
we don't have a large enough sample here to say.
> There's an image of copper dendrites on Steve Zeva's gallery
>
> http://stevezeva.homestead.com/
>
> http://stevezeva.homestead.com/Dendrite_1.jpg
>
> These tend to be inter-node rather than centrally expanding.
>
> A close examination of tin whiskers should reveal a characteristic three
> dimensional spike/thread detail. Not likely here.
>
creepers.
Cursitor Doom
Mar 18, 2016, 10:13:26 AM3/18/16
to
> They seem to emerge from under it and spread along the surface, but I
> can't confirm that yet as I've resisted disturbing them so far in case
> they disintegrate and defy further analysis.
some sort of breakdown of the clear coating which has enabled these
things to get a foothold. They then break out and traverse along the
board *on top* of the coating. So it's doubtful they could cause any
short circuits unless by sheer chance the tip of one of them hits another
spot of coating that's broken down above a trace - or a chip pin. When
touched with a scalpel blade they break apart readily into shards and can
be blown away by an air duster can.
The coating has lost its integrity and could probably be scrubbed away
with a toothbrush. I personally prefer to use clear varnish for my own
boards. It hasn't the depth that this coating has, but at least when it's
set, it's set for good.
I wonder what the reverse side looks like? Perhaps there's no coating at
all, in which case who knows what state it's in.
legg
Mar 18, 2016, 10:38:33 AM3/18/16
to
http://listserv.ipc.org/scripts/wa.exe?A1=ind1603&L=TechNet
Question is, what is your repair plan?
You don't seem to have any indication of the unit's present state
other than sticking it back in the car and seeing if the car starts.
No fb on xtal replacement yet.......
The blemishes you're chasing may have nothing to do with actual fault.
The spatter pattern is also suggestive of the impact from an external
source, such as a flicked paint brush.
The single metalic entrapment pictured should also flick off with a
knife blade. But without some before and after passive probing, you'll
never know if this did anything.
RL
Cursitor Doom
Mar 18, 2016, 11:24:05 AM3/18/16
to
On Fri, 18 Mar 2016 10:37:46 -0500, legg wrote:
> Technet link was previously posted.
>
> http://listserv.ipc.org/scripts/wa.exe?A1=ind1603&L=TechNet
Thanks, I hadn't spotted that link.
> Technet link was previously posted.
>
> http://listserv.ipc.org/scripts/wa.exe?A1=ind1603&L=TechNet
> Question is, what is your repair plan?
plans with this unit are to spend as little time as possible on it and if
it can't be fixed reasonably quickly, to get rid of it. Items like this
are way off-beat for me and I have a pile of other stuff more in my line
awaiting my attention in due course.
> You don't seem to have any indication of the unit's present state other
> than sticking it back in the car and seeing if the car starts. No fb on
> xtal replacement yet.......
higher priorities, plus avoiding the usual divorce threats.
> The blemishes you're chasing may have nothing to do with actual fault.
>
> The spatter pattern is also suggestive of the impact from an external
> source, such as a flicked paint brush.
straightaway. I shall have to post to the photo groups for adaptor ideas
to make it possible to post much better quality macro shots online than
the ones I'm pissing everyone off with at present.
> The single metalic entrapment pictured should also flick off with a
> knife blade. But without some before and after passive probing, you'll
> never know if this did anything.
Mike Tomlinson
Mar 18, 2016, 2:13:48 PM3/18/16
to
En el artículo <37cc548b-c211-4846...@googlegroups.com>,
pf...@aol.com <pf...@aol.com> escribió:
>why do the British drink
>warm beer?
So we can actually taste it. Have you drunk warm American beer? It's
icy cold to hide the fact that it tastes bloody awful. QED.
:)
--
(\_/)
(='.'=) Bunny says: Windows 10? Nein danke!
(")_(")
pf...@aol.com <pf...@aol.com> escribió:
>why do the British drink
>warm beer?
So we can actually taste it. Have you drunk warm American beer? It's
icy cold to hide the fact that it tastes bloody awful. QED.
:)
--
(\_/)
(='.'=) Bunny says: Windows 10? Nein danke!
(")_(")
Gunther Heiko Hagen
Mar 18, 2016, 2:51:14 PM3/18/16
to
On Fri, 18 Mar 2016 18:13:46 +0000, Mike Tomlinson wrote:
> En el artículo <37cc548b-c211-4846...@googlegroups.com>,
> pf...@aol.com <pf...@aol.com> escribió:
>
>>why do the British drink warm beer?
>
> So we can actually taste it. Have you drunk warm American beer? It's
> icy cold to hide the fact that it tastes bloody awful. QED.
>
> :)
They don't appear to use hops for flavouring in N. America and Australia,
> En el artículo <37cc548b-c211-4846...@googlegroups.com>,
> pf...@aol.com <pf...@aol.com> escribió:
>
>>why do the British drink warm beer?
>
> So we can actually taste it. Have you drunk warm American beer? It's
> icy cold to hide the fact that it tastes bloody awful. QED.
>
> :)
so it's not really beer at all but 'malt liquor' to be more accurate.
Young British men who don't know any better seem quite happy to drink
such monstrous concoctions as Coors, Bud and Fosters because they don't
know any better and fall for the flashy advertising and glitzy looking
dispensers. The best beers in the world - proper beers - are brewed by
the Belgians, the Czechs and the very best of all of course - the Germans.
Jon Elson
Mar 18, 2016, 3:05:21 PM3/18/16
to
Cursitor Doom wrote:
>
>> They seem to emerge from under it and spread along the surface, but I
>> can't confirm that yet as I've resisted disturbing them so far in case
>> they disintegrate and defy further analysis.
>
> Right, basically what I said above is correct. There seems to have been
> some sort of breakdown of the clear coating which has enabled these
> things to get a foothold. They then break out and traverse along the
> board *on top* of the coating. So it's doubtful they could cause any
> short circuits unless by sheer chance the tip of one of them hits another
> spot of coating that's broken down above a trace
Hmmm, very interesting. If they have GROWN out of the board, especially
>
>> They seem to emerge from under it and spread along the surface, but I
>> can't confirm that yet as I've resisted disturbing them so far in case
>> they disintegrate and defy further analysis.
>
> Right, basically what I said above is correct. There seems to have been
> some sort of breakdown of the clear coating which has enabled these
> things to get a foothold. They then break out and traverse along the
> board *on top* of the coating. So it's doubtful they could cause any
> short circuits unless by sheer chance the tip of one of them hits another
> spot of coating that's broken down above a trace
from the vias, then they have a really good chance of being conductive.
And, maybe the ones across the TOP of the coating are no problem, but if
there are some on the back side or under the coating, they could cause
trouble. If the conformal coat has broken down, moisture and various
contaminants could have gotten under it and started making conductive paths.
If the controller depends on some high impedance circuitry, that could cause
it to quit.
If these things are on TOP of the coating, then it should be easier to make
a conductivity measurement. (But, yes, I see you say they are brittle.)
Jon
Cursitor Doom
Mar 18, 2016, 5:00:45 PM3/18/16
to
On Fri, 18 Mar 2016 14:05:57 -0500, Jon Elson wrote:
> If these things are on TOP of the coating, then it should be easier to
> make a conductivity measurement. (But, yes, I see you say they are
> brittle.)
Indeed they are - very! Anyone who can come up with a method for
> If these things are on TOP of the coating, then it should be easier to
> make a conductivity measurement. (But, yes, I see you say they are
> brittle.)
establishing if they're conductive and if so, to what extent deserves a
Nobel Prize, I reckon.
Sjouke Burry
Mar 18, 2016, 7:27:02 PM3/18/16
to
Apply a very small drop of salt water to the tip of
one of those out grows then one side of your ohmmeter
to a ground and the other side gently touching the
drop of water.
If the whisker conducts, that should show up.
Cursitor Doom
Mar 18, 2016, 9:15:14 PM3/18/16
to
On Sat, 19 Mar 2016 00:26:58 +0100, Sjouke Burry wrote:
> Going for the nobelprice then. :)
> Apply a very small drop of salt water to the tip of one of those out
> grows then one side of your ohmmeter to a ground and the other side
> gently touching the drop of water.
> If the whisker conducts, that should show up.
Thank you for that, Sjouke. I'll ponder this idea of yours as I can see
> Going for the nobelprice then. :)
> Apply a very small drop of salt water to the tip of one of those out
> grows then one side of your ohmmeter to a ground and the other side
> gently touching the drop of water.
> If the whisker conducts, that should show up.
some merit in it. the only problem AISI is these fibres are so tiny it's
going to require a steady hand and a good eye - but I have neither! :(
However, it's very late here now so I'll report back tomorrow with the
results - *if* I can pull it off.
Mike Tomlinson
Mar 19, 2016, 9:29:06 AM3/19/16
to
En el artículo <nchih2$j56$1...@dont-email.me>, Gunther Heiko Hagen
<gunth...@quantserve.de> escribió:
>The best beers in the world - proper beers - are brewed by
>the Belgians, the Czechs and the very best of all of course - the Germans.
Yep. I was thrilled when I went in a little off-the-beaten-track bar in
a remote part of the Canary islands to find they had three chiller
cabinets stuffed with craft Belgian and German beers.
Have my tickets booked for Oktoberfest :)
<gunth...@quantserve.de> escribió:
>The best beers in the world - proper beers - are brewed by
>the Belgians, the Czechs and the very best of all of course - the Germans.
a remote part of the Canary islands to find they had three chiller
cabinets stuffed with craft Belgian and German beers.
Have my tickets booked for Oktoberfest :)
amdx
Mar 19, 2016, 3:41:25 PM3/19/16
to
On 3/17/2016 8:01 AM, MJC wrote:
> In article <nce05k$n7j$2...@dont-email.me>, cu...@notformail.com says...
> confusion! Even if all enamel is now also the sort that turns into flux
> if you try to solder the wire...
>
> Mike.
>
Far as I've seen, the latest change (20 yrs) was to a higher
temperature enamel that is Brown. The change was made for electric
motors because with VFD's they can run at higher temperatures.
Mikek
> In article <nce05k$n7j$2...@dont-email.me>, cu...@notformail.com says...
>>
>> Nowadays
>> all enamel copper seems to be clear, but back in the day the enamel was a
>> sort of deep plum shade - which is what I see here. I'll do some searches
>> for pictures of TW and see if some match what I see on this board....
>
> I didn't know modern enamel had gone clear. Sounds like a recipe for
>> Nowadays
>> all enamel copper seems to be clear, but back in the day the enamel was a
>> sort of deep plum shade - which is what I see here. I'll do some searches
>> for pictures of TW and see if some match what I see on this board....
>
> confusion! Even if all enamel is now also the sort that turns into flux
> if you try to solder the wire...
>
> Mike.
>
Far as I've seen, the latest change (20 yrs) was to a higher
temperature enamel that is Brown. The change was made for electric
motors because with VFD's they can run at higher temperatures.
Mikek
Sjouke Burry
Mar 19, 2016, 4:15:41 PM3/19/16
to
feed that to google pictures to see one. :)
MJC
Mar 19, 2016, 5:12:17 PM3/19/16
to
In article <56edb461$0$4110$e4fe...@textnews.kpn.nl>,
burrynu...@ppllaanneett.nnll says...
doubt Google will suggest that)...
Mike.
burrynu...@ppllaanneett.nnll says...
> >
> Eye sight is what made me buy a "jewelers headband loop",
> feed that to google pictures to see one. :)
Probably better to spell it "loup" if you want to do a search (though no
> Eye sight is what made me buy a "jewelers headband loop",
> feed that to google pictures to see one. :)
doubt Google will suggest that)...
Mike.
Cursitor Doom
Mar 19, 2016, 5:42:02 PM3/19/16
to
On Sat, 19 Mar 2016 21:15:10 +0100, Sjouke Burry wrote:
> Eye sight is what made me buy a "jewelers headband loop",
> feed that to google pictures to see one. :)
Yeah, I've got one with a little light in the centre; very useful! Still
> Eye sight is what made me buy a "jewelers headband loop",
> feed that to google pictures to see one. :)
got rotten motor skills, though.
legg
Mar 20, 2016, 9:44:00 AM3/20/16
to
dishwasher.
Depends on whether the aim is repair, or donation to science. If the
latter - ship to mfr in sealed bag with note attached - expect no
response.
RL
Cursitor Doom
Mar 20, 2016, 11:40:01 AM3/20/16
to
ungrateful bunch.
I'd like to power the board up and check for signs of life - see if that
xtal's working and so forth. But in view of those growths it seems
pointless unless I can get the back off and inspect the reverse side for
further signs of it spreading. But I don't want to risk damaging it in
the process. I'm not very good with practical things like that. They
invariably take FAR longer than I expect at the outset - and then I get
threatened with divorce. :(
legg
Mar 24, 2016, 7:21:57 AM3/24/16
to
On Fri, 18 Mar 2016 10:37:46 -0500, legg <le...@nospam.magma.ca> wrote:
<snip>
contaminated air hose jet.
RL
<snip>
>
>The blemishes you're chasing may have nothing to do with actual fault.
>
>The spatter pattern is also suggestive of the impact from an external
>source, such as a flicked paint brush.
>
Also, it brings to mind patterns produced by spatter from a
>The blemishes you're chasing may have nothing to do with actual fault.
>
>The spatter pattern is also suggestive of the impact from an external
>source, such as a flicked paint brush.
>
contaminated air hose jet.
RL
Michael A. Terrell
Mar 29, 2016, 11:27:40 AM3/29/16
to
Gunther Heiko Hagen wrote:
>
> On Fri, 18 Mar 2016 18:13:46 +0000, Mike Tomlinson wrote:
>
> > En el artículo <37cc548b-c211-4846...@googlegroups.com>,
> > pf...@aol.com <pf...@aol.com> escribió:
> >
> >>why do the British drink warm beer?
> >
> > So we can actually taste it. Have you drunk warm American beer? It's
> > icy cold to hide the fact that it tastes bloody awful. QED.
> >
> > :)
>
> They don't appear to use hops for flavouring in N. America
in many places.
Gunther Heiko Hagen
Mar 29, 2016, 6:22:53 PM3/29/16
to
On Tue, 29 Mar 2016 11:27:28 -0400, Michael A. Terrell wrote:
> Then explain why Florida has started farming hops instead of oranges,
> in many places.
For export, of course.
> Then explain why Florida has started farming hops instead of oranges,
> in many places.
Phil Allison
Mar 30, 2016, 2:17:00 AM3/30/16
to
Heiko Hagen wrote:
>
> They don't appear to use hops for flavouring in N. America and Australia,
>
** America produces 28,000 tonnes of hops per year - practically all of it going into beer. Only Germany produces more, with 34,000 tonnes.
>
> They don't appear to use hops for flavouring in N. America and Australia,
>
https://en.wikipedia.org/wiki/Hops#Cultivation_and_harvest
Thing is, they probably don't use enough of it in each barrel to suit you.
Small and craft brewers generally use a lot more malt and hops per barrel than the big commercial ones.
.... Phil
Michael A. Terrell
Apr 3, 2016, 12:15:03 AM4/3/16
to
0 new messages