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Electronics => Repair => Topic started by: hvontres on January 04, 2023, 07:11:45 am

Title: Help repairing HP 4294a Impedance analyzer
Post by: hvontres on January 04, 2023, 07:11:45 am

I am currently trying to revive an old agilent 4294 Impedance analyzer. Initial troubleshooting seems to point to a dead A9 floating power supply or a faulty A2 Source amp. Does anybody here have any leads on Internal documentation that could help track down the issue ? I kind of miss the detailed documentation that came with the older HP equipment.

Also, does anybody know of sources for spare parts for these units?

Thanks for your help,
Henry von Tresckow

Title: Re: Help repairing HP 4294a Impedance analyzer
Post by: rfengg on January 04, 2023, 02:35:21 pm

Hope the attached link to  doc helps......file is too large to post here......which parts are you looking for?

https://seabaugh.nd.edu/assets/330848/at_man_agilent4294aservicemanual.pdf

Title: Re: Help repairing HP 4294a Impedance analyzer
Post by: hvontres on January 04, 2023, 03:56:20 pm

Thanks for the link. Unfortunately, I already have that document and unlike the classic HP documents, it only really covers the overall system but has no info for board level troubleshooting.

At this point I think I would need the following parts:
A9 Floating supply
A59 LCD inverter

Possibly also a new A2 source board, but I hope it is just the missing 24V supply that is making it not work.

Thanks for your help.