I recently replaced the IRF1010E's in this amp they were blown in half, Anyway I replaced them and hooked it up it played for about 1-2 mins then POP and well you know what happened, it ate them again. Can anyone tell me what I missed?
s it even worth repairing again? It appears to be a nice amplifier.
Any help would be greatly appreciated.
s it even worth repairing again? It appears to be a nice amplifier.
Any help would be greatly appreciated.
Now that I have had the post in right place and Ive tried to refresh my mind with the tutorial, very informative by the way. I can get back to trying to explain what I have found. When I removed the blown FETs I noticed there were resisters that were pretty toasted so I removed one to try to read the color code but was not able to properly identify it. So I did measure them and all were in the 52 ohm range, but in the other post he said they were 47ohm gate resisters. Its been a few years since ive done any audio repair I usually stick to mechanical work but I do know a little and always willing to learn more. So please be patient with me.
Im getting 4 volts from the first 2 and the last 2 FETS(total of 8) I also tested the 4 undestroyed ones along side 2 new ones from the lot of 10 I bought and the were good.I am going to download the datasheets for the 4 transistors(2 A1023's and 2 C1027's) I am assuming are the driver transistors, should I pull them and test them?
An externally hosted image should be here but it was not working when we last tested it.
Ok if you zoom youll see where I put 4's on the FET pads that showed 4 volts and the 0's where no voltage was produced. hope this helps.
IT appears that there are several problems. You need to confirm that all of the gate resistors are within tolerance. I can't read the color code on them so I can't tell you what they're supposed to be.
The drivers also appear to be damaged. Remove them and check them.
Measure the DC voltage on the 3rd leg of the drivers after removing them.
The drivers also appear to be damaged. Remove them and check them.
Measure the DC voltage on the 3rd leg of the drivers after removing them.
An externally hosted image should be here but it was not working when we last tested it.
ok the driver transistors are definately part of the problem.(they are pulled and tested)
I managed to pull a color code from one of the gate resistors, 47 ohms.(all showed this ohm)
In the modified photo I tried to show my findings for voltage all inner pins of the group posted 4.6 volts.
Center pins of the 2 trannys closest to the FETS posted 11.5 volts.
Ok all 4 drivers are receiving 4.6V,center legs of C1027 are 11.5-12V,center legs of the A1023's are 0 ohms to ground. Lookin good, so if I replace to IRF1010E's(8 of them),8 47ohm 1/4 watt resistors, and 2 2SA1023's and 2 2SC1027's. Does that sound about right?Now when I tried to look up data sheets for the drivers I could only find them in a different packageing but will keep looking.
Should I reapply thermal silicon or use silicon insulator pads or both? Ive had people tell me use this or that, but you have been really knowledgeable so I trust what you say.By the way Thank You for helping me. Years ago I had a fork in the road,go mechanical or electrical im thinking maybe I should have went electrical.
You have to use something that is both thermally conductive and an electricall insulator between the transistors and the heatsink. If you use silicone insulators, you can use them without the heatsink compound. If you use hard insulators, you have to apply heatsink compound to the transistor and heatsink.
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