hello; I have a problem with my 100w subwoofer kit, the measurements I came out the right values but I test then he works but the heatsink gets super hot and I do not know how that happened, yesterday I test again and it does not work anymore?
If it works but the heatsink gets too hot, then there is probably a problem with the bias current setting.
You can check this by measuring the voltage over R60.
Make sure the transistorT7 and diode D15 make a good thermal contact with the heatsink to avoid thermal runaway of the circuit.
It is possible that due to this issue one or more semiconductors might have failed.
In such case, we recommend to replace all semiconductors of the power amp stage.
If you are unable to solve the problem, you can return the kit for inspection/repair.