info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
HP 3561A
176 views
Skip to first unread message
jurb...@gmail.com
Sep 26, 2015, 2:30:53 PM9/26/15
to
What there is of a service manual is at :
http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%203561A%20Service.pdf
I do believe an actual schematic would help. I need the vertical deflection circuit.
OK, I blew out the power supply by making a short with the probe at the input to the -12 volt regulator. Of course it has an obscure HP part number on it but I can see it is a simple 7912 regulator. It is possible I blew it shorting the input if it has alot of capacitance on the output but that is not really an issue right now. First I will get the power supply up again. The referenced URL there has some basic block diagrams, and I am pretty sure I just blew a fusible somewhere.
But the reason I was in there in the first place is because it has a fault in the vertical sweep - foldover. Like on a TV when the boost cap or circuit fails, EXCEPT on this baby it is at the bottom of the raster as it does not scan top to bottom, but bottom to top.
It is not easy to follow this circuit because of the two sided board, but not impossible. The problem is that those people could put anything anywhere, and do. I can tell the vertical output is common emitter complementary push pull. The collectors are hooked together and are the output high side.
I do not see a third "retrace" transistor anywhere, but knowing how engineers are it might be on the frikken control panel or something. Also, retrace boosters are hard to implement with a common emitter push pull circuit.
I actually cannot see the yoke, but observing the high side of the vertical output I know it has one because it looks pretty much like the yoke drive in a TV. If electrostatic it would just be a sawtooth wave.
I would really like to see a detailed schematic of the vertical circuit here. I do not just "try" parts to see if that was the fault usually and I am certainly not going to start on something like this. I know that in instrumentation I cannot get away with some of the shit you can flub in a TV set or a stereo. I learned the hard way that when they say 15 volts they do not mean 16.5 is OK, it usually is not.
The thing puts out the waveform incoming along with the spectral analysis at the top. A sine wave was showing what looks like severe crossover distortion in an audio amp, but another scope confirmed it was not like that. Looked a little closer and the raster is not filling the screen and there is a compression right there. I also think I am missing one of the function names. They are on screen next to the buttons and none of that lines up of course.
Anyway, I am seeing hints of a "Volume 2" of the service manual which I suspect contains the information I want. I have been almost everywhere and it is not to be found. If anyone has it I need it, even if you have it on paper and could scan me a JPG of the vertical circuit would be fine. (if you can't get my email from this post I will give it to you, unless you can Dropbox it or something)
Really, I can probably do it without but it would take a hell of alot more time.
Thanks in advance for anything helpful.
http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%203561A%20Service.pdf
I do believe an actual schematic would help. I need the vertical deflection circuit.
OK, I blew out the power supply by making a short with the probe at the input to the -12 volt regulator. Of course it has an obscure HP part number on it but I can see it is a simple 7912 regulator. It is possible I blew it shorting the input if it has alot of capacitance on the output but that is not really an issue right now. First I will get the power supply up again. The referenced URL there has some basic block diagrams, and I am pretty sure I just blew a fusible somewhere.
But the reason I was in there in the first place is because it has a fault in the vertical sweep - foldover. Like on a TV when the boost cap or circuit fails, EXCEPT on this baby it is at the bottom of the raster as it does not scan top to bottom, but bottom to top.
It is not easy to follow this circuit because of the two sided board, but not impossible. The problem is that those people could put anything anywhere, and do. I can tell the vertical output is common emitter complementary push pull. The collectors are hooked together and are the output high side.
I do not see a third "retrace" transistor anywhere, but knowing how engineers are it might be on the frikken control panel or something. Also, retrace boosters are hard to implement with a common emitter push pull circuit.
I actually cannot see the yoke, but observing the high side of the vertical output I know it has one because it looks pretty much like the yoke drive in a TV. If electrostatic it would just be a sawtooth wave.
I would really like to see a detailed schematic of the vertical circuit here. I do not just "try" parts to see if that was the fault usually and I am certainly not going to start on something like this. I know that in instrumentation I cannot get away with some of the shit you can flub in a TV set or a stereo. I learned the hard way that when they say 15 volts they do not mean 16.5 is OK, it usually is not.
The thing puts out the waveform incoming along with the spectral analysis at the top. A sine wave was showing what looks like severe crossover distortion in an audio amp, but another scope confirmed it was not like that. Looked a little closer and the raster is not filling the screen and there is a compression right there. I also think I am missing one of the function names. They are on screen next to the buttons and none of that lines up of course.
Anyway, I am seeing hints of a "Volume 2" of the service manual which I suspect contains the information I want. I have been almost everywhere and it is not to be found. If anyone has it I need it, even if you have it on paper and could scan me a JPG of the vertical circuit would be fine. (if you can't get my email from this post I will give it to you, unless you can Dropbox it or something)
Really, I can probably do it without but it would take a hell of alot more time.
Thanks in advance for anything helpful.
Jeff Liebermann
Sep 26, 2015, 3:32:44 PM9/26/15
to
On Sat, 26 Sep 2015 11:30:50 -0700 (PDT), jurb...@gmail.com wrote:
>Of course it has an obscure HP part number on it but I can see it
>is a simple 7912 regulator.
It might be a good idea to check. Google for "HP part number cross
>Of course it has an obscure HP part number on it but I can see it
>is a simple 7912 regulator.
reference" and you'll find various lists. This one looks good:
<http://www.sphere.bc.ca/download/hp_xref-free.pdf>
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
jurb...@gmail.com
Sep 27, 2015, 11:58:43 AM9/27/15
to
Thanks, that might come in handy.
Looks like I have to RTFM even with what I got. This thing shut down with a slip of the probe and now appears to need to be reset. There doesn't seem to be any bad components but there is no drive to the power supply choppers. I am going to make surer of that later today I think. It is difficult to access anything to test so I'll do hat I usually do - stick a wire on it and slide the card back in.
The way this thing is put together I can't even find the main transformer ! I pretty much know where it is but can't see hide nor hair of it.
This is another one where I look at how it is built and go "Why ?". They got the choppers on a standup car, the transformer on the motherboard and the rectifiers on another standup card. The logical assumption is they intended for service to be able to be performed on a modular level. All fine and good, but a part of me goes "Are you kidding ?".
I can't bitch. I couldn't design the thing at all. But I can go "Huh ?".
Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
Looks like I have to RTFM even with what I got. This thing shut down with a slip of the probe and now appears to need to be reset. There doesn't seem to be any bad components but there is no drive to the power supply choppers. I am going to make surer of that later today I think. It is difficult to access anything to test so I'll do hat I usually do - stick a wire on it and slide the card back in.
The way this thing is put together I can't even find the main transformer ! I pretty much know where it is but can't see hide nor hair of it.
This is another one where I look at how it is built and go "Why ?". They got the choppers on a standup car, the transformer on the motherboard and the rectifiers on another standup card. The logical assumption is they intended for service to be able to be performed on a modular level. All fine and good, but a part of me goes "Are you kidding ?".
I can't bitch. I couldn't design the thing at all. But I can go "Huh ?".
Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
John Robertson
Sep 27, 2015, 1:23:39 PM9/27/15
to
> Looks like I have to RTFM even with what I got. This thing shut down with a slip of the probe and now appears to need to be reset. There doesn't seem to be any bad components but there is no drive to the power supply choppers.. I am going to make surer of that later today I think. It is difficult to access anything to test so I'll do hat I usually do - stick a wire on it and slide the card back in.
connectors. Take a close look at the sockets to see if the plastic is
breaking down and the body of the edge connector socket is spreading out
at the middle.
Of course clean the PCB edge connectors, etc...
John :-#)#
--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
>
> The way this thing is put together I can't even find the main transformer ! I pretty much know where it is but can't see hide nor hair of it.
>
> This is another one where I look at how it is built and go "Why ?". They got the choppers on a standup car, the transformer on the motherboard and the rectifiers on another standup card. The logical assumption is they intended for service to be able to be performed on a modular level. All fine and good, but a part of me goes "Are you kidding ?".
>
> I can't bitch. I couldn't design the thing at all. But I can go "Huh ?".
>
> Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
>
With everything on sub-boards the first suspects are the card edge
> The way this thing is put together I can't even find the main transformer ! I pretty much know where it is but can't see hide nor hair of it.
>
> This is another one where I look at how it is built and go "Why ?". They got the choppers on a standup car, the transformer on the motherboard and the rectifiers on another standup card. The logical assumption is they intended for service to be able to be performed on a modular level. All fine and good, but a part of me goes "Are you kidding ?".
>
> I can't bitch. I couldn't design the thing at all. But I can go "Huh ?".
>
> Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
>
connectors. Take a close look at the sockets to see if the plastic is
breaking down and the body of the edge connector socket is spreading out
at the middle.
Of course clean the PCB edge connectors, etc...
John :-#)#
--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
JC
Sep 27, 2015, 3:54:24 PM9/27/15
to
group including a PSU schematic in the files section. You might want to
sign up with them. A quick read through and there's a lot about flyback
burnup but I'm not familiar with the unit. I can send the PSU schematic
if your email address is valid, size 3MB
Jeff Liebermann
Sep 27, 2015, 5:15:51 PM9/27/15
to
On Sun, 27 Sep 2015 08:58:39 -0700 (PDT), jurb...@gmail.com wrote:
>Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
I couldn't find anything on a "reset" procedure.
>Anyway, thanks. And if you catch wind of any "reset" routine for HP stuff let me know. I am going to triple check that there are no blown components, like fuzibes n shit.
Maybe try the operating manual instead of the service manual:
<http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%203561A%20Operating.pdf>
<http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%203561A%20Service.pdf>
Incidentally, the 7912 regulator is short circuit protected and should
easily recover from a short to ground. It's probably something else
that blew. I would guess(tm) a fuse.
jurb...@gmail.com
Sep 27, 2015, 9:13:33 PM9/27/15
to
>"With everything on sub-boards the first suspects are the card edge
>connectors. Take a close look at the sockets to see if the plastic >is
>breaking down and the body of the edge connector socket is spreading >out
>at the middle."
Not this time. I understand what you are saying but in this case that isn't it. I did look at the connectors actually and they are that blue plastic. I KNOW that blue plastic is not stronger or better due to its color but I think they have a tendency to only use that color for really good plastic. Thaat is really only an impression I got, but it is based on real world observations.
>connectors. Take a close look at the sockets to see if the plastic >is
>breaking down and the body of the edge connector socket is spreading >out
>at the middle."
At any rate, I looked at them pretty good and they are not splitting. And the fact that the new fault came after I sliped with the probe, that ain't it, at least right now.
>"Of course clean the PCB edge connectors, etc... "
jurb...@gmail.com
Sep 27, 2015, 9:19:39 PM9/27/15
to
jurb...@gmail.com
Sep 27, 2015, 9:31:16 PM9/27/15
to
>"Incidentally, the 7912 regulator is short circuit protected and >should
>easily recover from a short to ground. It's probably something else
>that blew. I would guess(tm) a fuse. "
Yes, but the center pin is input and I thought it might short the protection diode or something. I am sure something upstream went, unless it is now in software. That worries me because them fuckers could make it so the SMPS will never get drive again unless you buy tool J-1120953A.
>easily recover from a short to ground. It's probably something else
>that blew. I would guess(tm) a fuse. "
The file I already had indicates no real hard fuzibles that would go. And I have physically looked. I will look again. I really want an easy solution, like some little one ohm resistor or some shit. It should not be that hard, it was a simple short circuit.
Who knows, this may totally overshadow the vertical sweep problem. But this is not something I can just st aside.
JC
Sep 27, 2015, 10:45:37 PM9/27/15
to
jurb...@gmail.com
Sep 28, 2015, 12:43:08 AM9/28/15
to
I got it. Thanks.
Next, once it is up and running again I got to tackle that vertical circuit. I noticed alot of hash on the output of a 12 volt regulator, not sure if that is the cause of the problem. I don't even know what supplies it runs off of. I did see the vertical drive waveform but I did not note its amplitude. It could have been ten volts or fifty. I wasn't looking for amplitude, I was looking for that little glitch in it. It was there. It indicates an upset for the feedback loop, because of the inability of the circuit to impress the voltage on the (yoke) coil to result in a sawtooth current.
We will be getting back to that soon. I will check everything.
Next, once it is up and running again I got to tackle that vertical circuit. I noticed alot of hash on the output of a 12 volt regulator, not sure if that is the cause of the problem. I don't even know what supplies it runs off of. I did see the vertical drive waveform but I did not note its amplitude. It could have been ten volts or fifty. I wasn't looking for amplitude, I was looking for that little glitch in it. It was there. It indicates an upset for the feedback loop, because of the inability of the circuit to impress the voltage on the (yoke) coil to result in a sawtooth current.
We will be getting back to that soon. I will check everything.
JC
Sep 28, 2015, 10:56:31 AM9/28/15
to
http://www.qservice.tv/vpasp/shopexd.asp?id=843&bc=no
There's a guy here with one, recent blog, maybe you can help each other out.
http://jimmyauw.com/2015/03/01/hp-agilent-3561a-dynamic-signal-analyzer/
Phil Hobbs
Sep 30, 2015, 3:14:17 PM9/30/15
to
http://electrooptical.net/www/sed/HP3561A_ServiceManual.pdf
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Michael A. Terrell
Oct 17, 2015, 8:00:54 PM10/17/15
to
Phil Hobbs wrote:
>
> On 09/28/2015 10:56 AM, JC wrote:
> > On 9/28/2015 12:43 AM, jurb...@gmail.com wrote:
> >> I got it. Thanks.
> >>
> >> Next, once it is up and running again I got to tackle that vertical
> >> circuit. I noticed alot of hash on the output of a 12 volt regulator,
> >> not sure if that is the cause of the problem. I don't even know what
> >> supplies it runs off of. I did see the vertical drive waveform but I
> >> did not note its amplitude. It could have been ten volts or fifty. I
> >> wasn't looking for amplitude, I was looking for that little glitch in
> >> it. It was there. It indicates an upset for the feedback loop, because
> >> of the inability of the circuit to impress the voltage on the (yoke)
> >> coil to result in a sawtooth current.
> >>
> >> We will be getting back to that soon. I will check everything.
> >>
> >
> > If you want to spend some beans the manual is here for download
> >
> > http://www.qservice.tv/vpasp/shopexd.asp?id=843&bc=no
> >
> > There's a guy here with one, recent blog, maybe you can help each other
> > out.
> >
> > http://jimmyauw.com/2015/03/01/hp-agilent-3561a-dynamic-signal-analyzer/
>
> And if not, I posted it here:
>
> http://electrooptical.net/www/sed/HP3561A_ServiceManual.pdf
has both the service and the operating maunuals. Keysight it the latest
name change for HP test equipment.
jurb...@gmail.com
Oct 17, 2015, 11:48:06 PM10/17/15
to
They actually do not have volume two of the service manual. We just got it, ON PAPER. Quite illustrating. The unit is up and running again with the replacement of a 7912. Apparently my shenanegins made leaky the device inside there.
I am back to the vertical sweep problem now. I'll probably get back into it next weekend. Give it some thought in the meantime.
I am back to the vertical sweep problem now. I'll probably get back into it next weekend. Give it some thought in the meantime.
jurb...@gmail.com
Oct 25, 2015, 2:13:22 AM10/25/15
to
So now, with the coveted volume two in hand, I see they call the vertical horizontal and the horizontal vertical. The print does depict what I had been reverse engineering. I think on page 7-249.
The vertical circuit does not use a boost cap, switcher or diodes as far as I can tell. Simple transconductance (current) amp run off a ramp.
It has vertical foldover, that is usually caused by not enough voltage peak on retrace. In an old TV it would almost certainly be a bad lytic. But this does not use that type of circuit.
Actually it might be a bit of fun doing this. I have to put leads on the board to test it because it is shielded. What's more, the way it is I have to use insulated wire. Alot of times I have just used solder, but that won't work with this.
The vertical circuit does not use a boost cap, switcher or diodes as far as I can tell. Simple transconductance (current) amp run off a ramp.
It has vertical foldover, that is usually caused by not enough voltage peak on retrace. In an old TV it would almost certainly be a bad lytic. But this does not use that type of circuit.
Actually it might be a bit of fun doing this. I have to put leads on the board to test it because it is shielded. What's more, the way it is I have to use insulated wire. Alot of times I have just used solder, but that won't work with this.
jurb...@gmail.com
Oct 26, 2015, 3:01:13 PM10/26/15
to
Well well well, they did not misname them, the raster lines are vertical. So I finds a cap off the flyback causing the compression.
Now the phasing is off. I looks like there is a foldover on the bottom but there isn't. Turning up the brightness to the point of seeing the whole raster it is fine.
Now the phasing is off. I looks like there is a foldover on the bottom but there isn't. Turning up the brightness to the point of seeing the whole raster it is fine.
jurb...@gmail.com
Oct 30, 2015, 11:17:09 PM10/30/15
to
Phil Hobbs
Oct 31, 2015, 4:44:39 PM10/31/15
to
On 10/30/2015 11:17 PM, jurb...@gmail.com wrote:
> How the hell do these posts get on other websites ?
>
> http://www.edaboard.co.uk/hp-3561a-t553464.html
>
They're just like Google Groups--parasitic but sometimes useful.
> How the hell do these posts get on other websites ?
>
> http://www.edaboard.co.uk/hp-3561a-t553464.html
>
electronicsrelated.com is the same sort of thing.
0 new messages