19-05-2012, 07:04 PM
Ahem - you pay attention, young David 
Sometimes, disturbing the 5-pin connector can change the way these things behave, and as he would have done that to get the chassis out...
I always advise against cutting the screen, because when the whiskers catch up with another electrode, you have a dead transistor (and perhaps not enough of a screen lead left to attach to the charged capacitor!). Seen that plenty of times :-)
To be fair to the transistors themselves, the junctions are pretty good - let's face it, they're 50 years old now. It's a shame that many manufacturers continued to use the AF11x range long after the problem was discovered, and it's also amusing that lead-free solder and platings have seen the whisker problem reoccur. History, it seems, can teach us nothing
All the best,
Mark
Quote:Yes indeed, but these things have a habit of changing their spots when you start poking around inside them. Had you repeated that test after your earlier work today, then the next move would have been the gram input socket - with certainty.
Sometimes, disturbing the 5-pin connector can change the way these things behave, and as he would have done that to get the chassis out...
I always advise against cutting the screen, because when the whiskers catch up with another electrode, you have a dead transistor (and perhaps not enough of a screen lead left to attach to the charged capacitor!). Seen that plenty of times :-)
To be fair to the transistors themselves, the junctions are pretty good - let's face it, they're 50 years old now. It's a shame that many manufacturers continued to use the AF11x range long after the problem was discovered, and it's also amusing that lead-free solder and platings have seen the whisker problem reoccur. History, it seems, can teach us nothing
All the best,
Mark
