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
--
http://www.linetec.nl