i found circuit board damage internally, sucks to be me

i unhooked the subs and powered on, same problem

multimeter says 4 ohms.

have the amp open now, looks like someone has been in it already, some of the board screws are stripped.

ohms are fine, they are 8 ohm but i have the wired parallel to 4.

picked up one of these amps on craigslist cheap- 200 bucks. was super cold out the day i bought it, 20 below 0. didnt have time to hook it up and test but the guy assured me it was good to go so i took his word for it. i got around to hooking it up today and as it powers on my subs make a thump, the...