HP 214B Pulse Generator repair question

[Richard Rasker]

Hello,

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

 

[Richard Rasker]

[snip Hewlett-Packard 214B Pulse Generator]
....

....

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

Best regards,

Richard Rasker

 

[Richard Rasker]

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

Best regards,

Richard Rasker

try this;
http://www.home.agilent.com/agilent/techSupport.jspx?pid=214B:epsg:pro&
pageMode=MN&cc=US&lc=eng&pselect=SR.PM-Search%20Results%20-
%20Manuals.Manuals

or;
http://tinyurl.com/2fsq9m8

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).

Richard Rasker

 

[Bob Pownall]

On 9/6/2010 7:57 AM, Richard Rasker wrote:

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

 

[Meat Plow]

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].

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.

 

[Archon]

Hello,

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

Artekmedia have the full manual, I guess you can get it as download off
their website if you contact tthem, ( Artekmedia.com ) but its listed
as a CD on Ebay , search # 370162101455

JC

 

[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.

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].

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.

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

 

[Meat Plow]

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.

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?

 

[Bob Pownall]

OK, I got some responses but I'm not sure how useful they are.

http://cgi.ebay.com/HP-214B-Operati...01455?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...N&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...942664?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...625?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-Operati...01455?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.

Richard Rasker

 

[Richard Rasker]

don't forget you can ASK QUESTIONS of the seller on the eBay site,-before-
making a bid or buy.

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,

Richard Rasker