Hi diyAudio Team members, my name is Alfonso, Im from Mexico, Im Electronic Engineer and I love the car audio, as a hobby, Im starting to repair subwoofers and power amplifiers.
at this moment, I have a JL Audio JX500/1 that had the power supply mosfets and a couple of BJT transistors damaged, I replaced all of the for brand new components, same batch, the transistors replaced were:
8 RFP70N06 (not sure if those are the original ones, it looks like those were replaced at least once before)
4 TTC5200, original ones were from toshiba, but I bought brand EVVO, I got them from digikey
4 TTA1943, original ones were from toshiba, but I bought brand EVVO, I got them from digikey
I checked the fets driver TL494CN with a scope, it is wirking fine, after that, I turn the amp on and it changed from protect to power mode, I connected a subwoofer and it looks like it is working fine, but after around 10-15 mins working, the output stage section is It's heating up very fast, power supply stage is very stable and is not hot, I decided to turn the amp off before it get damaged again.
The output driver transistors used in this amp are the TP41 and TP42, I dont know if those are the originals or were replaced before, in some threads I read that these transistors are not good as drivers, d you know if these transistors are the original ones used by this amp?
what can be causing that the amp is heating up very fast only in the output power transisitos (C5200 & A1943)? something else that I can check?
I really appreciate your help.
Thank you
at this moment, I have a JL Audio JX500/1 that had the power supply mosfets and a couple of BJT transistors damaged, I replaced all of the for brand new components, same batch, the transistors replaced were:
8 RFP70N06 (not sure if those are the original ones, it looks like those were replaced at least once before)
4 TTC5200, original ones were from toshiba, but I bought brand EVVO, I got them from digikey
4 TTA1943, original ones were from toshiba, but I bought brand EVVO, I got them from digikey
I checked the fets driver TL494CN with a scope, it is wirking fine, after that, I turn the amp on and it changed from protect to power mode, I connected a subwoofer and it looks like it is working fine, but after around 10-15 mins working, the output stage section is It's heating up very fast, power supply stage is very stable and is not hot, I decided to turn the amp off before it get damaged again.
The output driver transistors used in this amp are the TP41 and TP42, I dont know if those are the originals or were replaced before, in some threads I read that these transistors are not good as drivers, d you know if these transistors are the original ones used by this amp?
what can be causing that the amp is heating up very fast only in the output power transisitos (C5200 & A1943)? something else that I can check?
I really appreciate your help.
Thank you
This amp is a class D amplifier. Some pictures would do wonders. I have the same amp and it has none of the mosfets listed. I have my version open and in front of me currently.