Suddenly there was no sound, and the CD changer would not turn on (as it's powered by the amp). The headunit powers on just fine.

Does the amp have an external fuse? Could it be easily repairable? Should I just order a new used amp for $100? I also had some issues with the volume dropping down, especially in cold weather?

Cheers!

The HK amps were wired on the same fuse as the power antenna. If your power antenna rises, its not a fuse.

jagosaurus, I have an amp if your unable to get yours to work. Just let me know. Micksjag.

Thanks, checked fuse 9 in the trunk, no problem with it. I have a new amp on the way, so ill test that one first!

Replaced the amp, made sure the antenna moves and the radio receives a signal (ST lights up), but still no sound. Cd changer not connected, but if I try to connect it I can't switch to it. What gives??

Double check both radio fuses: #9 and #12 on the passenger side fuse box. One is battery power and the other is ignition power to the headunit.

Both fuse 9 and 12 passenger side are fine. And the headunit powers up. Strange!