HP 214B Pulse Generator repair question
Richard Rasker
I've been asked to fix a special piece of lab equipment, a Hewlett-Packard
214B Pulse Generator, dating back from 1980 or thereabouts.
The problem is relatively straightforward: a chain of components in
the -155V supply has blown:
* PCB fuse F602, value unknown
* Q601 and Q602 (MJ15003)
Since the fuse (F602) has literally exploded, there's no way to determine
its original current rating.
The question of course is what caused this rather convincing supply failure;
the main suspects here are the output tubes V401 and V402-- but I can't see
what types these are either. I have a schematic diagram, but no part list,
so I'm rather stuck.
Does anyone have any experience with these beasties? Or could someone point
me to a service company which may perhaps provide the information on the
fuse and the tubes? AFAICT, it's still a rather expensive piece of
equipment (~$ 6,000), so I really want to try and repair it.
Thanks in advance for any information,
Best regards,
Richard Rasker
--
http://www.linetec.nl
J. Todd
spam...@linetec.nl says...
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
Richard Rasker
> In article <4c84f341$0$729$7ade...@textreader.nntp.internl.net>,
> spam...@linetec.nl says...
>> Hello,
>>
[snip Hewlett-Packard 214B Pulse Generator]
...
>> I have a schematic diagram, but no part list, so I'm rather stuck.
...
> The manual is on the BAMA site. google BAMA
Thank you for your swift reply -- but unfortunately, that sites offers the
exact same diagram/manual file I already have. The trouble is that there's
no parts list included, so I can't look up any component values.
So any suggestions are still appreciated :-)
Jim Yanik
news:4c8508bf$0$729$7ade...@textreader.nntp.internl.net:
try this;
http://www.home.agilent.com/agilent/techSupport.jspx?pid=214B%3Aepsg%3Apro&
pageMode=MN&cc=US&lc=eng&pselect=SR.PM-Search%20Results%20-
%20Manuals.Manuals
or;
http://tinyurl.com/2fsq9m8
--
Jim Yanik
jyanik
at
localnet
dot com
Michael A. Terrell
http://cp.literature.agilent.com/litweb/pdf/00214-90012.pdf might
have what you need.
--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.
Richard Rasker
Great find, but once again, it doesn't feature a parts list that I can find;
the text also doesn't mention the type or ratings of output tubes or fuse.
I'm afraid that all manuals available on the Internet are based on this
one -- they're eerily alike, especially the front page photo scan is
identical in all cases. I'll try contacting Agilent, but something tells me
that this may well be the only information they have available,
so the outlook isn't particularly favourable :-(
Anyway, thank you for your efforts (mr. Terrell as well).
Bob Pownall
<snip>
> I have a schematic diagram, but no part list,
> so I'm rather stuck.
I used to work at HP. I'll post to an HP alumni technical list and see
if anybody who used to design / build / support these things responds.
Bob Pownall
whit3rd
> I've been asked to fix a special piece of lab equipment, a Hewlett-Packard
> 214B Pulse Generator, dating back from 1980 or thereabouts.
>
> The problem is relatively straightforward: a chain of components in
> the -155V supply has blown:
> * PCB fuse F602, value unknown
> * Q601 and Q602 (MJ15003)
>
> Since the fuse (F602) has literally exploded, there's no way to determine
> its original current rating.
Look for labels, or silk-screened indications of the fuse type and
rating...
you never know.
It might be possible to analyze the exploded bits, of course.
Collect
them all!
If it helps, MJ15003 is rated for 20A, max. The
safe-operating-area limit is a polygon on log(I)/log(V) paper with
nodes at
[ 20A, 10V], [5A, 50V], [0.5A, 140V].
Meat Plow
I've repaired some old SW radio gear where it was impossible to get
technical data. That never stopped me though. I understood the circuits,
mixers, IF, Hartley osc etc.. and applied what I knew typical values
existed for the circuit to work. Similar to what you suggest. Same with
more recent mosfet power amp from the 80's. Sound Code Systems or SCS.
Couldn't find at the time (too early for the primitive internet search
engines) any service errata. But I knew the parameters of the devices
and what they should spec and effected a repair. The amp is still in
service here. If the OP has a couple blown MJ's and a toasted fuse that
shouldn't require scientific intervention.
--
Live Fast, Die Young and Leave a Pretty Corpse
Jim Yanik
maybe these links will help;
http://www.ko4bb.com/Manuals/03)_Manual_and_Test_Equipment_Links.php
good luck.
Archon
their website if you contact tthem, ( Artekmedia.com ) but its listed
as a CD on Ebay , search # 370162101455
JC
Richard Rasker
I'm legally responsible for whatever goes wrong (further damage or injury)
if I put in the wrong parts, most notably fuses. Furthermore, this thing is
used in a university laboratory by quite a number of people, so I really
need to get it right. So in this particular case, guesswork is out of the
question (but if I had to guess, I'd say that the fuse should be something
between 1 and 4 amps, and the tubes look quite similar to PL519's).
Richard Rasker
That would be great, thanks!
Jeff Liebermann
<spam...@linetec.nl> wrote:
>Thank you for your swift reply -- but unfortunately, that sites offers the
>exact same diagram/manual file I already have. The trouble is that there's
>no parts list included, so I can't look up any component values.
>
>So any suggestions are still appreciated :-)
Try getting it from the Agilent site:
<http://cp.literature.agilent.com/litweb/pdf/00214-90012.pdf>
I'm having a problem downloading it (hangs 25% of the way through) so
I can't tell if it's the same as the one on BAMA.
--
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
Jeff Liebermann
wrote:
>Try getting it from the Agilent site:
><http://cp.literature.agilent.com/litweb/pdf/00214-90012.pdf>
>I'm having a problem downloading it (hangs 25% of the way through) so
>I can't tell if it's the same as the one on BAMA.
Never mind. It's the same as the one on BAMA. No parts list.
whit3rd
> I'm legally responsible for whatever goes wrong (further damage or injury)
> if I put in the wrong parts, most notably fuses.
Put it another way: you're responsible, and want to get the machine
both working and working safely. The fuse selection isn't a 'legal'
decision, it's a technical one. You'll use technical data, judgement,
and take technical advice.
The 'correct' value fuse can't be critically important, if its failure
spewed
bits of metal in all directions the first time it interrupted the
circuit...
and you still want the machine back into operation.
Meat Plow
This guy just doesn't seem to get it. I could see if he was working on a
GE MRI machine or Agilent DNA spectrometer. But this is an obsolete pulse
generator from the 80's. Besides repair is he also legally responsible
for calibration and certification?
Jeff Liebermann
<spam...@linetec.nl> wrote:
>>>> Since the fuse (F602) has literally exploded, there's no way to
>>>> determine its original current rating.
Place an amps guesser in place of the fuse and measure the operating
current. Ummm... replace the blown transistors first. Then select a
value about 2-3 times the measured current. If you're charging a big
filter capacitor, consider a slow blow fuse.
>I'm legally responsible for whatever goes wrong (further damage or injury)
>if I put in the wrong parts, most notably fuses.
If that's true, then walk away. You were given an impossible
assignment, where there is insufficient information to return the unit
to its original operating condition without you having to make a
decision. Should a liability situation arise, one item the court
might need to determine is whether you are competent to repair the
equipment. Be sure to document your decisions, supply references,
sources, and justifications for your actions. Attorneys just love
impressive documentation and paper trails.
I haven't seen any mention of dried out electrolytic capacitors, which
are the most common source of failures in 20+ year old equipment. An
ESR tester will be required to make the determination. If it still
has the original electrolytics in the power supply section, I would be
seriously worried. I just repaired an HP 8620A sweep generator
mainframe. The major problem was dried out electrolytics.
<http://members.shaw.ca/swstuff/esrmeter.html>
I buy a lot of older HP test gear off ebay as well as older
radios. Most of this gear is 25-60 years old and needless
to say, the condition of the electrolytic capacitors is
somewhat suspect...
>Furthermore, this thing is
>used in a university laboratory by quite a number of people, so I really
>need to get it right.
No problem. Get one of these university people involved in the repair
so that you have someone available to blame should things go awry.
Students are expendible anyway. Be sure to let them make a few
decisions. If litigation and liability are you primary concerns, it's
always best to have a scapegoat handy.
>So in this particular case, guesswork is out of the
>question (but if I had to guess, I'd say that the fuse should be something
>between 1 and 4 amps, and the tubes look quite similar to PL519's).
Life is nothing but a succession of calculated risks, which are call
guesswork when they fail.
Spend $150 on a carcass. Look inside for the missing values. Steal
what parts are needed:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350353282625>
>Richard Rasker
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com je...@cruzio.com
# http://www.LearnByDestroying.com AE6KS
Bob Pownall
http://cgi.ebay.com/HP-214B-Operating-Service-Manual-COMPLETE-/370162101455?pt=BI_Books_Manuals&hash=item562f616ccf
(or http://tinyurl.com/3xp4sa8)
is an eBay listing for the HP 214B Operating and Service Manual. It
claims to be 147 pages, and thus more complete than the 123 page manual
available for download from the Agilent website:
http://www.home.agilent.com/agilent/techSupport.jspx?pid=214B%3Aepsg%3Apro&pageMode=MN&t=80091.k.3&co=165945.i.4&cc=US&lc=eng&sm=g
(http://tinyurl.com/2v5wkvl)
The eBay price is $7.50 + $2.25 shipping, so how far wrong could you go?
http://cgi.ebay.com/AGILENT-HP-214B-REPAIR-MAINTENANCE-MANUAL-/7601942664?pt=BI_Books_Manuals&hash=item1c51c7088
(http://tinyurl.com/2ulxvfb)
is a PDF of the 214B repair & maintenance manual. Again, at $2.99 +
$1.99 shipping, how far wrong could you go?
http://cgi.ebay.com/Agilent-HP-214B-Pulse-Generator-Parts-Repair-/350353282625?pt=LH_DefaultDomain_0&hash=item5192aed641
(http://tinyurl.com/3xoerhp)
is a dead 214B that could maybe be used for parts.
Sorry I couldn't come up with better answers to your questions.
Bob Pownall
Richard Rasker
> OK, I got some responses but I'm not sure how useful they are.
>
>
http://cgi.ebay.com/HP-214B-Operating-Service-Manual-COMPLETE-/370162101455?pt=BI_Books_Manuals&hash=item562f616ccf
> (or http://tinyurl.com/3xp4sa8)
> is an eBay listing for the HP 214B Operating and Service Manual. It
> claims to be 147 pages, and thus more complete than the 123 page manual
> available for download from the Agilent website
OK, thanks, I think I'll give this one a go. The equipment is definitely
worth it, and besides, half an hour of my time is rather more expensive
than this.
Jim Yanik
don't forget you can ASK QUESTIONS of the seller on the eBay site,-before-
making a bid or buy.
Richard Rasker
OK, thanks for the tip , but I just ordered the manual -- and it did indeed
contain the parts list. I hope to get to work on it next week. And oh, the
fuse was 3 amps slow, and the end tubes were 7534 (E130L, nothing like the
PL519 at all).
So in all, I got the information I needed, and now I just hope that I won't
need to hunt down new end tubes ...
Anyway, thanks again, best regards,