HP-35 power unit: Failing Vgg voltage

[teenix]

Being your dad's it would be something special.

The transistors could be working if the other rails are ok, so I would be checking for failed capacitors and germanium diodes on the Vgg output. Cheap and easy to replace.

Maybe check the 60uF input capacitor as well.

Have a look for corrosion around the transformer.

Laporte's old web site has some interesting HP-35 info.

cheers

Tony