HP Power supply 0950-1879 problems

[Harvey White]

I have one of these, made to fit in the 1650/1651 logic analyzer
series (and a few scopes, too, IIRC). It starts up, then shuts down,
then starts up again, shuts down again.

Behavior is the same in and out of the analyzer, all voltages seem to
be correct, out of the analyzer is running a 2-3 amp load on the 5.2
volt supply (per HP instructions).

Any idea of where the problem might be? No obvious signs of damage.

Any links to a schematic? I can fix it if I have a schematic. (Trying
to avoid having to trace out the schematic, myself...)

HP service manual specifies this as a black box swapout. I have a
replacement supply, so the analyzer is up, but I'd just as soon fix
the old supply so I'd have a spare.

Thanks,
Harvey

 

[Jorgen Lund-Nielsen]

Harvey White wrote:

I have one of these, made to fit in the 1650/1651 logic analyzer
series (and a few scopes, too, IIRC). It starts up, then shuts down,
then starts up again, shuts down again.

Behavior is the same in and out of the analyzer, all voltages seem to
be correct, out of the analyzer is running a 2-3 amp load on the 5.2
volt supply (per HP instructions).

Any idea of where the problem might be? No obvious signs of damage.

Any links to a schematic? I can fix it if I have a schematic. (Trying
to avoid having to trace out the schematic, myself...)

HP service manual specifies this as a black box swapout. I have a
replacement supply, so the analyzer is up, but I'd just as soon fix
the old supply so I'd have a spare.

Thanks,
Harvey

Check all the electrolytics for ESR with a ESR-Meter.
Capacitance is secondarily

Jorgen