I got the Alpine amp stated in the title from a family member and was told that he didn't know if it worked or not. After wiring it up and trying to turn it on the amp went right into protection mode. Yes my wiring was right I opened it up and a mosfet labeled N0D C25P20FR on spot D607 and one labeled N0E KCF25A20 bon spot D606 were busted. Would it be posible to bypass the protection circut or should I replace the part.
If I do replace the part the replacements I found only had the C25P20FR and the KCF25A20 labeled on the data sheet, would these work?
If I do replace the part the replacements I found only had the C25P20FR and the KCF25A20 labeled on the data sheet, would these work?
Those aren't FETs. They're rectifier diodes and will read as shorted in the board. Is that reading of a short across the outer legs what you're referring to?
The blue shows that the two outside pins have continuity and the red shows wich pins have continuity with the middle pin
Unless you read a short from the center leg to the outer legs, they're OK.
I'd pull the board. The attached photo shows how the transistors (different model) are clamped to the metal risers. Leave the transistors clamped to protect them. Look for broken connections on the large white resistor solder connections.
I'm assuming that you checked all other components that are clamped to the heatsink.
'Continuity' doesn't mean anything. What's the resistance reading?
I'd pull the board. The attached photo shows how the transistors (different model) are clamped to the metal risers. Leave the transistors clamped to protect them. Look for broken connections on the large white resistor solder connections.
I'm assuming that you checked all other components that are clamped to the heatsink.
'Continuity' doesn't mean anything. What's the resistance reading?
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There is 1.9 ohm across the two outer pins on each. On d606 0 ohms between the left pin and center pin and 6.55Mohms across middle and right. For d607 11.37 across left and middle and 0 across middle and right. Going to pull the board now.
The board it out and I have a few question areas with the first image I don't know if all of those traces should be connected and the second one just shows the solder pins for d606 and d607.
I can't find the big white resistor you are talking about and how do you want me to check the the rectifier unless you just want me to probe it again
I can't find the big white resistor you are talking about and how do you want me to check the the rectifier unless you just want me to probe it again
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Desolder the center terminal and make sure it's no longer in contact with the circuit and re-check from the center to the outer legs.
Using a multimeter, a lot of points will look like they're directly connected because they are connected by inductors, transformers, fuses... This is why the outer terminals of the rectifiers appear to be shorted, normally They're connected together through the secondary windings of the transformer. To DC, they are 0 ohms but to AC, they're not nearly the same.
Using a multimeter, a lot of points will look like they're directly connected because they are connected by inductors, transformers, fuses... This is why the outer terminals of the rectifiers appear to be shorted, normally They're connected together through the secondary windings of the transformer. To DC, they are 0 ohms but to AC, they're not nearly the same.
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So I desoldered the middle pins but I can't get the connection between the pin and the board to break. I still rechecked and marked wich two were getting 0 ohms. I checked all four of the large white resistors and got 1.3 on all legs.
I just noticed what looks like where wires might have shorted to the outer metal ground and if some did that could have caused damage I should look for. I don't know where the damage would be though. Maybe on the line in?
I just noticed what looks like where wires might have shorted to the outer metal ground and if some did that could have caused damage I should look for. I don't know where the damage would be though. Maybe on the line in?
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The problem with the resistors is broken connections. If the rectifiers are shorted, the resistor connections are not the problem. It's simply one of the first things you check when these amps are going into protect mode.
You'll have to remove the rectifier completely to check it.
You'll have to remove the rectifier completely to check it.
Both d606 and d607 transistors are reading 0.55 all around except for the two outer ones on both are not reading anything
I was asking about the output transistors (connected to the large white resistors). The rectifiers appear to be OK.
You could have a bad rail capacitor if the output transistors are all OK.
You could have a bad rail capacitor if the output transistors are all OK.
Check what I sent pics of and all seems good the only thing I saw was the wire. One end is labeled LP002 and the other is labeled LP003
