Help with Germanium PNP transistors needed.

[Nigel Goodwin]

i'm thinking he should also do another C-E measurement with the leads reversed from the first measurement and add that to the chart.

if i was fixing this item purely for functionality, i would try using silicon devices and changing the base bias. i would make it a reversible fix however just in case somebody were interested in buying it.

That's rather assuming the devices are faulty in the first place?, as I've said all along you should fault find, not randomly rip bits out and try and do passive tests on them (particularly on leaky germanium power devices).

 

[unclejed613]

true, shotgunning is the worst approach (besides, it can cause serious mistakes on getting the proper transistors in their proper place and proper pinout when reassembling). it's a stereo amp, so it's much easier to do good/bad comparison of the emitter, base, and collector voltage measurements. he's more likely to find an open or high ESR electrolytic cap in the signal path than a bad transistor.

 

[Nigel Goodwin]

he's more likely to find an open or high ESR electrolytic cap in the signal path than a bad transistor.

Actually not at all, those wouldn't affect the DC conditions of the amplifier on any way, if it was a capacitor then leaky or S/C would be the reason.

As far as high ESR goes, that's really only an issue with switch mode supplies, actual lack of capacitance is the common failure mode on older non-SMPS electrolytics.