Hi, I'll start by saying that I'm not an expert and I've reached a point where I don't know what to try/do anymore...
Starting from the beginning: I opened this subwoofer for the first time with a very strong smell of burnt electrical components, I realize that on the amplifier board there is a hole between V+ OUT and GND about the size of a finger, the damaged components were the shorted mosfets, two damaged zener diodes and two capacitors. I bought everything, I fixed the hole by cutting the pcb and putting a piece of a perforated board.
I had no problems connecting mosfets and capacitors, the only doubt I had was connecting Z2 to gnd (because of that arrow on the datasheet). Before connecting everything and powering it I checked the amplifier board thoroughly, every single component seems ok to me, same thing for the main board (the one with the power supply) and finally the jack board if you can call it that... I connected everything to the toroidal transformer, the mosfets short out and the fuse blows, obviously there was and is not a short circuit on any pin, I suspect that the cause of this problem is the low quality mosfets (IRF9640/640 taken from aliexpress), what do you think?
To ALMOST completely exclude the other two boards I tried to power them first without the amplifier board, and then with the amplifier board but without the mosfets, the fuse does not blow, the LED works and the relay trips. I also measured the voltages on the mosfet pins, more or less around 10 volts, some 9.5 or 7.
I don't know what to do, I've already asked for some advice but in the end it didn't lead me anywhere, is there anyone who can try to help me? I'm attaching the link to the datasheet and a couple of photos, if you need other photos/information/measurements let me know.
Thanks in advance
Datasheet: https://elektrotanya.com/harman_kard.../download.html
Photos: https://imgur.com/a/QLxfmaz
Starting from the beginning: I opened this subwoofer for the first time with a very strong smell of burnt electrical components, I realize that on the amplifier board there is a hole between V+ OUT and GND about the size of a finger, the damaged components were the shorted mosfets, two damaged zener diodes and two capacitors. I bought everything, I fixed the hole by cutting the pcb and putting a piece of a perforated board.
I had no problems connecting mosfets and capacitors, the only doubt I had was connecting Z2 to gnd (because of that arrow on the datasheet). Before connecting everything and powering it I checked the amplifier board thoroughly, every single component seems ok to me, same thing for the main board (the one with the power supply) and finally the jack board if you can call it that... I connected everything to the toroidal transformer, the mosfets short out and the fuse blows, obviously there was and is not a short circuit on any pin, I suspect that the cause of this problem is the low quality mosfets (IRF9640/640 taken from aliexpress), what do you think?
To ALMOST completely exclude the other two boards I tried to power them first without the amplifier board, and then with the amplifier board but without the mosfets, the fuse does not blow, the LED works and the relay trips. I also measured the voltages on the mosfet pins, more or less around 10 volts, some 9.5 or 7.
I don't know what to do, I've already asked for some advice but in the end it didn't lead me anywhere, is there anyone who can try to help me? I'm attaching the link to the datasheet and a couple of photos, if you need other photos/information/measurements let me know.
Thanks in advance
Datasheet: https://elektrotanya.com/harman_kard.../download.html
Photos: https://imgur.com/a/QLxfmaz
