dawsonaudio
Well-known member
I'm testing some transistors off of my Ampex MM1100 transport pwa. They are RCA125/NTE262. I've got them both pulled off the board. Normally, when I've tested transistors in the past, I use the diode setting and go from base to collector/base to emitter and then reverse the polarity and do the same. I usually get a small reading and then OL/nothing when reversing the polarity. These are PNP transistors so I place the negative on the base and test as I explained above.
My problem is that I'm getting a small voltage reading when I switch the polarity and place the positive lead on the base and negative lead on the emitter. I'm also getting a positive voltage reading when I place the positive lead on the collector and negative lead on the emitter. I get OL/nothing when I place the positive lead on the base and negative lead on the collector.
I know this is a darlington type so maybe the normal test doesn't apply. I'm obviously doing something wrong. I've got some brand new NTE262 alternatives and they are doing the same thing.
Any suggestions?
Thanks,
Nate
My problem is that I'm getting a small voltage reading when I switch the polarity and place the positive lead on the base and negative lead on the emitter. I'm also getting a positive voltage reading when I place the positive lead on the collector and negative lead on the emitter. I get OL/nothing when I place the positive lead on the base and negative lead on the collector.
I know this is a darlington type so maybe the normal test doesn't apply. I'm obviously doing something wrong. I've got some brand new NTE262 alternatives and they are doing the same thing.
Any suggestions?
Thanks,
Nate