I have an SWR WM12 combo. It has been sitting in my buddy's basement studio for the last six months and I have only used it sparingly since I purchased a head/cab setup. Last night I didn't feel like hauling my amp head over there and decided to just play through the WM12. I wasn't getting the volume I was accustomed to so I decided to run my 4x10 (I keep it down there all the time so I don't have to haul it around) through it as an extension. It was dark and I have maybe hooked up an extension to the SWR one other time. I didn't notice that there were two output jacks on the back panel. Unfortunately, I ended up hooking the 4x10 into the headpphone jack instead of the extension cab jack. After playing for about 20-30 minutes I smelled something. I turned everything off, found the problem, and let it cool off. Hooked it up properly and jammed for an hour. No apparent problems. We took a break and when I went to turn on again, no sound. The power light comes on; I get a signal to the tuner output and the headpone jack (w/headphones!), but nothing through the internal speaker or the extension output. I know I am an idiot. Live and learn. Can anyone give me an educated guess as to the severity of the damage? Can it be repaired? Will it be cost-effective given that it was probably only worth $200-$250 anyway? Thanks.