Im troubleshooting a PS problem with this amp. FETs were BUZ102 and were destroyed. I removed them all. Gate resistors are good; 75ohm.
Its using LM324 (BA10324A) for Latch and TL494.
IC1 TL494
1. 0.086
2. 4.75
3. 4.75
4. 0.215
5. 1.426
6. 3.414 (Sawtooth)
7. 0
8. 14.45
9. 0.689 (Flat vDC. No drive)
10. 0.689 (Flat vDC. No drive)
11. 14.45
12. 14.45
13. 4.91
14. 4.91
15. 4.91
16. 13.71 (Too high?)
IC2 LM324
1. 0.486
2. 2.787
3. 0
4. 0.960 <-- Shouldn't this be ~14vDC?
5. 0.959
6. 0.959
7. 0.959
8. 0.046
9. 0.867
10. 2.184
11. 0
12. 0.868
13. 2.787
14. 2.326
Anything pop out as to why pins in question are not as I would expect? Especially TL494 pin 16 and LM324 pin 4?
Its using LM324 (BA10324A) for Latch and TL494.
IC1 TL494
1. 0.086
2. 4.75
3. 4.75
4. 0.215
5. 1.426
6. 3.414 (Sawtooth)
7. 0
8. 14.45
9. 0.689 (Flat vDC. No drive)
10. 0.689 (Flat vDC. No drive)
11. 14.45
12. 14.45
13. 4.91
14. 4.91
15. 4.91
16. 13.71 (Too high?)
IC2 LM324
1. 0.486
2. 2.787
3. 0
4. 0.960 <-- Shouldn't this be ~14vDC?
5. 0.959
6. 0.959
7. 0.959
8. 0.046
9. 0.867
10. 2.184
11. 0
12. 0.868
13. 2.787
14. 2.326
Anything pop out as to why pins in question are not as I would expect? Especially TL494 pin 16 and LM324 pin 4?
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Yes, LM324 and the lile quad opamps have their supply pins at 4 & 11. 4 is positivo and 11 negativo or ground.
Suggest to save the mosfet's untill last moment, when you see a good pwm at their gates. Well defined, not too close to 50%. In any case my suggestion is to replace gate resistors and drivers.
15 and 16 of TL494 are the current limiter. Perhaps a sense resistor dissapeared during the catastrophe.
Suggest to save the mosfet's untill last moment, when you see a good pwm at their gates. Well defined, not too close to 50%. In any case my suggestion is to replace gate resistors and drivers.
15 and 16 of TL494 are the current limiter. Perhaps a sense resistor dissapeared during the catastrophe.
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Aborted. Board PS section too physically damaged to consider a repair. The fets burnt a good chunk of the board, extra crispy. After consideration I determined the repair to be unviable.
Received a second Thor X amp this week which has the same problem. Cooked well-done PCB under the PS FETs rendering a similar result - no-go. This is about the 4th Thor X Ive seen like this.
Also I have a Venus X... That one I was able to repair but the PS section had some damaged traces and is nearly similar in design to a Thor X before the Toroid.
Where these amps under-built in the PS or is there something else I am missing? I'm sending the Venus X with IRFZ48 and 47 ohm gate resistors. Amp has good PS drive signal
Also I have a Venus X... That one I was able to repair but the PS section had some damaged traces and is nearly similar in design to a Thor X before the Toroid.
Where these amps under-built in the PS or is there something else I am missing? I'm sending the Venus X with IRFZ48 and 47 ohm gate resistors. Amp has good PS drive signal