fried amp?

i wired the amp up and connected the battery only to find smoke coming from the amp... upon openning the amp.. i saw i had fried a transistor thats clamped under the heatsink.

anyone know what might have caused this? and would it be too costly to repair?

sorry for double posting..

just to add more details.. i have a 4 ga wire from the battery down... and is fully insulated and while running it down.. it seemed fine.. and the wire is still alright and it didn't get hot when it fried the amp. ground also seems ok. i only hooked up the Power ground and remote wire.. and i guess that should be ok.. just to see if the amp was turning on.. instead it smoked and a pop went off.. and i opened it to see black soot coming from the small transistors that act as a power supply..

any hunches?

thanks

not new.. second hand..... but nvm.. i tried connecting the amp again yesterday just to try one last time.. and it miraculously worked!..

the only thing that was weird was.. even with the gains on both channels set to the minimum, when i turned the HU volume max.. it was actually quite loud..

now i'm just gonna spend some time fine tuning the gains.. but was just wondering, how does clipping actually sound like? is the sound muddy? or does the speaker make a crackling sound?

regarding me having a transistor fried in the amp, i was just wondering if this will cause the amp to still function but output less power on possibly one or all of the channels? i was just wondering because i heard that this might be the short protection circuit (yeah found a small short in the wire and was taken care of) in the amp and that it was still functioning fine.