Perfect, thank you so much. I bought 50x IRF540A since i realized they are some what hard to come by. Ill post back some more info once i replace them.
The ohm led turns on 2 seconds after the amp turns on, however the amp does NOT stop producing audio. All 4 channels produce clean audio. The amp is drawing about 10 amps at idle.
10 amps at idle is far too much. The bias is likely too high. Rotate all of the bias pots approximately 1/8th turn counter-clockwise to see if the idle current drops.
After turning the pots 1/8th of a turn counter clockwise the idle still remains at 10 amps, i noticed as soon as the low ohm light comes on that is when the amperage jumps to 10
Let it cool down. When it's cool, power it up and monitor the temperature of the heatsink. Where does it begin to heat up first, behind the outputs or behind the power supply FETs?
the 4th set of output transistors get hot, all the other output transistors and power supply fets are cool to to touch. Also when i plug a rca into the right rear channel, the crossover module begins to make a hissing noise.
After adjusting the pot counter clockwise for channel 4 the temperature of the output transistors stil get hot very fast
I checked them all again, all gate resistors are with in tolerance. I just replaced the two output transistors that were getting hot, low ohm light is off now, but i hear a hissing noise coming from the transformer.
yes all channels are operating correctly as of now, but i have the low ohm light will come back shortly.
If you operate the amp without the heatsink, the outputs can fail within seconds. That may be what happened to the outputs that failed.