Amp problem

Hello guys

i have a small problem with my car amp, as when i start the music, i can only hear it by putting my ear on the speaker, and when i disconnect the 12v power it works fine for a split of a second.i am pretty sure all the connections are made well, so what can it be?bad capacitor? bad mosfet?what/where should i check?

here is a picture of the amp board circuit

thanks in advace for an answer 😀