I have another problem NAD. I purchased this knowing it was needing repair. When I opened it up it smelled like it was in a house fire. I cleaned it up and it looks like it was never touched. So, I plugged it into my DBT and Vairac and was pleased to see no smoke or bright bulb. Now is where the fun begins. I decided to test it and low and behold it was fine. I ran load test with 4 and 8 ohm loads. Distortion was fine. Output was great. Perfect. Then I decided to recap it and put new relays in it. Now it stays in protect. I used all good new tested caps. I know the old adage of if it not broke don't fix it but if you saw the physical condition and smell of this thing you might of just used it for parts. This is frustrating because I'm not an electronic engineer but I have experience with this hobby for years. Any ideas?
Yes. Check every single component, you replaced that they are polarized correct.
After that, check every single soldering you´ve done.
As you said yourself, everything was perfectly fine, until you "messed" with it.
Don´t be offended, but to me it seems, that the only logical fix is to undo your own errors
At the factory we used to steam clean computer boards that had been badly abused. 72 hours at 130 f in a dry environmental chamber, many of them begin to work again.
If you are experienced, it is now more productive to analyze the circuit for the defect, rather than replacing every cap again. What is the DC value of each channel going into the protect relay? greater than 200 mv? That is bad.
Where does the incorrect voltage begin? Examine for errors around that point. If no excess DC voltage going out, maybe there is an error in the caps of the protection circuit.
I try to test my amp after every 2 components replaced, so I can zero in on what I did wrong. It is one of the last 2 components I put in. However some packages are so difficult to power up and power down that this is not possible. Lots of case assembly/disassembly required to get the board from accessible to funtional again. I have found Peavey is careful to design the package so repair is possible by changing the order of the driver board stack or something. (PV-1.3k) Other models not so much.
If you are experienced, it is now more productive to analyze the circuit for the defect, rather than replacing every cap again. What is the DC value of each channel going into the protect relay? greater than 200 mv? That is bad.
Where does the incorrect voltage begin? Examine for errors around that point. If no excess DC voltage going out, maybe there is an error in the caps of the protection circuit.
I try to test my amp after every 2 components replaced, so I can zero in on what I did wrong. It is one of the last 2 components I put in. However some packages are so difficult to power up and power down that this is not possible. Lots of case assembly/disassembly required to get the board from accessible to funtional again. I have found Peavey is careful to design the package so repair is possible by changing the order of the driver board stack or something. (PV-1.3k) Other models not so much.