Hey guys, I posted in 2nd gen IS forums but hoping to get any info I can!

I dropped my car off to get a FP change. I get my car back and now the car has no audio. I have a 1200w kicker amp installed along with the factory amp, and 10" kicker sub installed that was working perfectly fine prior. I took it back to them and they did a quick look and couldnt come up with anything. and am taking it back tomorrow for them to have more time. Weird thing is, i kept hitting the power on and power off to the radio and it actually came on and worked. But i turned the car off and back on and now its not working again. Everytime I turn the radio on i just get a low constant hum from my sub.

I've tried only stuff i know about:
disconnecting and reconnecting the battery.
Checking any fuses related to the audio
Ran the radio in diagnostic mode
I got 2/4 that say good. P1C6 says CHEC and so does N050 but the others are fine.

Thank you guys for your help!

 

Also from what I'm told they did not touch anything electrical except for jumping the vehicle (they said my vehicle died in their parking lot awaiting maintenance) and whatever would be under the back seat by the pump.

 

SO after talking with a friend he mentioned to check the other side (car side) of the of the grounding lead to the battery and it made me think about when i was at the shop.. when I had the mechanic go through his steps of touching the electrical system i remember noticing the weird spot he put my grounding cable on the batter and it clicked, that he just used a little bit of leverage and angle to hold the lead on... so i grabbed it and shook it a bit and it was tight but it came a little loose and i shimmied it off the battery and repositioned it, tightened it down and boom...radio was working again.

Apologize for the waste of a post but if anyone runs into an issue...it could help!