Circuit for HP3421A Data aquisition

[Barrie Carruthers]

It may sound incredible but we are still using HP 85's and HP 3421A's in our workplace. Slowly, the HP3421A's are dying, and to get them up and running again I dearly need a technical service manual or the circuit diagram of the motherboard. Can anybody help?

[RamLab]

Hello Barrie,

Good to see you are still using the HP3421A's.
I do to, however mostly as MUX infront of a HP34401.
But sometimes I bring out the old Thermo Couples. I still need
to build a connection box for K-couples.

RamLab

[Diego Diaz]

You've got mail.

Cheers.

Diego

[Barrie Carruthers]

Thanks for your responses guys. Now the drama starts while I try to nut out what all these error codes are really trying to tell me. Cheers

[RamLab]

Hi Barrie,

The error codes you can find in the Operating manual on page 18.
On one of the HP3421A's I get an Error 0.
Most likely due to moving the 44462A Units.
On the other one a 19... it took me a while to realize that that one
is under HPIB control, so that's the HPIB address.

Regards,

RamLab