No sound from left channel on power amp

I've got an Audiolab 8000P power amp in bi-amp mode. Just the other day, I noticed that I couldn't hear the "bass" from my left speaker. I ruled out that it was the speaker cuz I swapped them and same thing happened with the other. I checked the cables and source and ruled out that this problem was caused by any of them. So, this was the power amp I'm using for the low frequencies. I can power it up and one channel is fine. Any DIY suggestions other than bringing it in for repairs?

I do not own that amp but my suggestion is to look at your fuses,almost all of my amp problems were due to a bad or blown fuse some uses a resistor.

maybe very minor,check the left channel fuses/resistor.

hope that is all,good luck.

Open the cover (or read your owner's manual) and look for fuses* in the powersupply. Lots of amps have them.

* I don't mean the main AC-power fuse.
There may also be rail fuses along each bank of transistors that could blow (Acurus amps are like that). Have you tried contacting the manufacturer (if the owner's manual provides no guidance)?
Careful when changing fuses, use plasic fuse pliers. Remember risk of shock even if your amp is unplugged. Also risk of shorting something and frying your amp. Im sure most everyone knows this stuff but a little reminder cant hurt.
Contact Aragon. The customer service is great. They sent me fuses for free a couple of years ago.
Thanks a lot for your input guys. The manual doesn't say much. I just ended up bringing it back to the dealer I bought it from to make the repair just in case I make matters worse. Thanks again for the advice.