Need help on identifying amp defect Options

[soulsearchingsun]

I'm having issues with my mid-90s Sony solid state amp.
In particular the right channel is of lower volume (~-12dB in my measurements) and the sound is distorted in a way that there is noise added when I feed a signal to the amp. On silent parts, there is no additional noise. I ruled out the signal source and the speakers as the cause, it has to be the amp. I looked inside to see if I can find burned components, but I haven't had luck yet. I can't see the whole circuit board without disassembly (which I haven't done yet) though.

I uploaded a file here, with the following setup:
sound card output -> amp line level input; amp speaker out -> sound card line level input & speakers

Could anyone give me hints where I should look for the defect? Is this typical for some specific defect?
Thanks a lot!

edit:link now pointing to upload thread

This post has been edited by soulsearchingsun: Mar 1 2012, 14:32

[pdq]

We could probably look for some characteristic distortion resulting from a common failure mode (without even looking/listening I am betting blow drive transistor), but is it really worth it? The likelihood of it being something simple/inexpensive to fix is small, and the cost of an excellent replacement is quite modest, so I think you should just bite the bullet, so to speak.