These are nice units. The main problem we see are blown fuses on one of the amp driver boards. This is caused by two disintegrating "CLASS A" microswitches mounted behind the front panel, visible in your .jpg2. They are supposed to lower the power supplies in Class A mode, but when they crumble, they create power that the outputs cannot tolerate. The other problem these have are intermittent feed thrus in the rear jack board, which is actually fairly accessible. Once you put $30 in parts into it you can sell it for a minimum of $250. Don't dump it. I can give you something for it in broken condition, or help you fix it.