Amp Troubleshooting

[corporate]

All I'm getting from my amp (MTX Thunder 502) and sub (12") is... nothing. Except for squeels when I turn the knobs. I've checked everything I know of to check, including:

1)Running another RCA cable from the Head Unit (Alpine CDMA 7875)
2)Substituting another amp in this one's place - same outcome
3)Checked, Rechecked, Reset and Reconfigured Head Unit settings (Sub - ON, the amp is remotely controlled directly from the head unit)
4)Ran an 1/8" to RCA from my Ipod and laptop directly to amp (and secondary amp... does it need a powered signal for that to work?)
5)Confirmed Volumes and Ground Connection

Light is on and amp/sub sometime put out a continuous tone depending on the source (head unit vs. ipod vs. laptop)

Circuit City installed the wiring and another amp that was later stolen, and since I bought and just connected this amp, they won't test it (for free at least)

I installed a new alternator after it ran my battery dead - you think that would have anything to do with this? The car sat for about 4 months... (used the motorcycle)

Any ideas?

[DJ Hellfire]

Check your main fuse. Some amps can still light up the power LED off just a remote signal and ground.

Check for proper polarity for the speaker wires to the sub/s.

Check the RCA out of you radio to another source, like a home stereo receiver. Bring the receiver out to the car with an extension cord, and plug the RCA from the HU into the receiver. Then plug some headphones into the receiver and see if your HU is outputting sound. This will confirm whether or not your radio or RCA cable was damaged during the theft.

Try another set of RCA cables.

Make sure the sub output on your radio is turn on and the volume for the sub out is not set to 0 or off.

[corporate]

Check your main fuse. Some amps can still light up the power LED off just a remote signal and ground. Confirmed - still powered

Check for proper polarity for the speaker wires to the sub/s. Confirmed - switched a few times (does it really matter, or does just reverse the direction of the sub

Check the RCA out of you radio to another source, like a home stereo receiver. Bring the receiver out to the car with an extension cord, and plug the RCA from the HU into the receiver. Then plug some headphones into the receiver and see if your HU is outputting sound. This will confirm whether or not your radio or RCA cable was damaged during the theft. Okay - check back soon after I try this...

Try another set of RCA cables. Already did that

Make sure the sub output on your radio is turn on and the volume for the sub out is not set to 0 or off. Already did that

[|2oo]

headunit rca must be gones = dead

[corporate]

If that is the case... I've needed a new head unit anyways. Still have to check with another receiver though.

Will update.