I have a little transistor radio that was drawing excessive power from the battery. It was about 125mA at 6 volts which is 10 times too much. I found I could bend the circuit board to eliminate the problem. So, I studied the thing for an hour or so and found the problem had something to do with the audio output transformer. This radio uses an input and output transformer in a push pull arrangement. So, I used a soldering iron to heat the 5 terminals of the output transformer and the problem went away. Radio works fine now. But the question is, the output transistors were getting warm which indicated the excessive current was flowing through the output transistors. With two transformers, one for input and one for output, how is it possible for the transistors to overheat with only some problem with the output transformer?
.- posted
6 years ago