I have been trying to diagnose this older Harmon/Kardon receiver and I've found the transistors have been overheating on the surround channel board. The main chip is an integrated darlington pair. I have no experience with these. There are two transistors and one resistor in it. I've been told that it is almost impossible to use the diode check on a DMM like a normal transistor to check if it is open or short. Is this true? I'm getting a reading when I measure the collector-emmitor on one way which from what I understand of a normal NPN, is indicating a bad transistor, but it does the same thing when I test one of the ones from a good working channel. I've taken the chips out of circuit before testing. Don't know what I'm missing. Any resources or advice that I'm missing would be greatly appreciated.
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