Help with HP 3450B Multi-Function Meter needed

[Rodeodave]

Hi,

I'd like to get a faulty HP 3450B Multi-Function Meter running again. The unit seems to power up, some of the display's nixie tubes light up (and stay lit...) and a few relays go click, but that's it. The buttons don't light up and unit doesn't respond to anything.

I really don't know where to start, does someone have experience with this device and can provide hints? It's too beautiful to toss it out or gut it for parts...

Thanks,

dave

[tomchr]

The service manual is available for download on Agilent's website. If the schematics are too low resolution to read, try contacting Artek Media or Manuals Plus.

~Tom

[gootee]

After a careful detailed inspection, by eye, of all internals, check the rail voltages, first. If any are out of spec, at all, find out why and fix that before proceeding much further.

That unit is very old so I would consider replacing all of the electrolytic capacitors in the power supply, and then elsewhere if necessary, unless you have an ESR meter and can check them. (Or, if you have a scope and a pulse or square wave generator, you could try using the method at TESTING ESR OF ELECTROLYTIC CAPACITORS, without an ESR meter .)

I would also get some Caig De-Oxit and treat all of the switches, etc, and anything internal or external that can be unplugged, and all connectors (See caig.com for specific recommendations and products for special metals and conductive plastic pots).

Cheers,

Tom Gootee

[Rodeodave]

Wow, that was fast. Thanks for the link to the manual, I was looking for one all over, but not thoroughly enough it appears.

I'll check the voltages, maybe they give me an idea of what's wrong.

Thanks!