What is wrong with my Parasound HCA-1000?

Im wondering if anyone can help me troubleshoot my amplifier. I have a parasound ive been using for years and i think one of the inputs is bad. I hook directly into it and the left channel gives sound but has loud popping and the sound is very soft. The right channel works great and the sound is amazing. Now if i switch to bridge mode the sound works great as well. Bridge mode uses the same input as the right channel. My questions are could this be just an input issue or is the one channel shot? Also im looking to sell this amp because i replaced it in my home theater with a denon 4308ci because i wanted to simplify my system. So should i pay to fix it then sell it or should i sell it as is? any insight would be greatly appreciated.
Check the fuses. I've owned several amps that once the fuses blew, it still produced sound kinda like you are describing. Worth a look.
i'd try to eliminate simple causes first, which happen more than you'd think:
try swapping interconnects
try switching speaker wires/speakers
clean input rcas with deoxit--could be corrosion
if none of the above work, you might have a bad capacitator, which is easy to fix, or something more complex

your hca1000 is a good amp--the market for a properly functioning one is probably $250-300 (you might get $100 in its present condition), so depending on repair cost it's probably worth servicing
I'd check output transistors. They may not be short to cause amp shut down, but possibly went bad.
Ty very much for the responses ill go ahead and give it a try. I hooked the same speaker into both sides of the amp and switched around rcas. i will try to see if there is any corrosion b4 going further
In terms of resale, there is usually a big difference between the earlier HCA-1000, and the later John Curl redesigned HCA-1000A