Good. Now that you have symetric voltages on the plus and minus side, just check the power transistors.
By power transistors do you mean the outputs?
By power transistors do you mean the outputs?
Yes. Those you disconnected before.
........ if I have some doubts in measurement , desoldering and lifting one end of resistor is enough to clear doubt .
same applies for diodes
also - fastest way is to , one by one, desolder each semiconductor , test it and put it back or replace , if bad .
http://www.diyaudio.com/forums/pass-labs/55055-threshold-400a-parts-substitution-mods.html
Here NTE54/55 is offered as sub to FT317/417 and it looks same as MJE15030/31. They also offer "matched pairs".
FT317 NTE Equivalent NTE54 NPN audio power amplif... - Wholesale Electronics
NTE54 - NTE ELECTRONICS - BIPOLAR TRANSISTOR, NPN, 150V, TO-220 | Newark element14
Here NTE54/55 is offered as sub to FT317/417 and it looks same as MJE15030/31. They also offer "matched pairs".
FT317 NTE Equivalent NTE54 NPN audio power amplif... - Wholesale Electronics
NTE54 - NTE ELECTRONICS - BIPOLAR TRANSISTOR, NPN, 150V, TO-220 | Newark element14
I am still missing something somewhere. I rechecked everything and found a 300 ohm resister at 1k. Every thing else seems fine. Here are voltage readings at the transistors taken with 10 volts +/- input. Maybe someone will see something and give me a clue.
trans #
400and4000 B
![17160809902_4473cfa3d0_b.jpg](https://farm8.staticflickr.com/7587/17160809902_4473cfa3d0_b.jpg)
trans #
![16976381369_351f97c6aa_c.jpg](https://farm9.staticflickr.com/8747/16976381369_351f97c6aa_c.jpg)
![16972440635_fd617fb424_c.jpg](https://farm9.staticflickr.com/8742/16972440635_fd617fb424_c.jpg)
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- Threshold 4000 repair. Need some help.