How do you properly check a darlington driver?

Golf schrieb:

The NTE 2547 is an NPN darlington transistor, the complementary one would be the NET 2548 PNP darlington...

You're sure it is connected in this manner? In must HO stages you'll find pulses with about 1,2kV peak voltage on the collector against Gnd.

May be the NTE switches the B+ in respect of standby/on.

It isn't clear what function this transistor has in this circuitry... You have schematics?

- Udo

Not yet. I am trying to repair without the added cost of this. Yes, it is connected like this, almost. I left out a few low ohm resistors, a diode and the flyback between the emitter and the Hot collector. I'm not sure of this transistors function either, but the Hot collector voltage is supplied from this transistor from what I have seen and tested so far. I'm not sure how this transistor is supposed to be biased for least amount of resistance between the emitter and collector. One thing I should mention - the voltages I have taken are with this power board out of the set. I didn't think this would change the voltage readings I am getting at the Hot collector. I am going to remove the transistor from the circuit and test it's function. Until then maybe someone knows how this thing functions. Thanks.