I bought a Yorkville XM200 1x15 off of eBay. It arrived Friday, and when I plugged it in, it sounded as though the speaker had blown and the amp had a short. It was very static and would not hold a tone. And what sound it would make would cut in and out. I called the seller and we made arrangements for a FedEx damage claim. I took it to a shop to have an repair estimate written up, and when the guy plugged it in, everything was fine. I brought it back home, and it has played fine all weekend. The guy at the shop mentioned that it could have condensation from the humidity or that the speaker might have "jumped the gap" (?) and could have gone back in somehow. Has anyone had anything like this happen? The combo plays fine now, but I don't want to accept it as is if it has possible damage that could show up in a couple weeks or months.