So heres the deal, I had not played on my halfstack for a solid 2 years. One day on a whim I decided I'd give it another whirl so I waited for it to warm up. After a few minutes when it was warm enough to play I started to turn up the volume and when I moved the volume knob up at all it released an unbearable high pitched squel. It sounded like feedback except that was impossible as the volume was so low, Id say about 0.3ish. I am hoping that someone out there can tell me what is wrong and how I can fix it. Did something break or is it just because I left it sitting for so long? And on a side note the last time I did play it there was nothing wrong with it and it worked perfectly. I really hope it is a simple solution as I've heard of repairs for instruments costing just as much if not more than the instrument itself.