My friend give me this one for try to repair it. There is low and very distorted sound on both channels. I started to check voltages on the board, in middle of checking i've noticed that schematic what can be found on the net doesnt fit in this part: resistors R723 and 724 (2,2K) are not in this amplifier, they are changed with something that look like thermal switch or something like that, on both chanels there is this green part with sign 17A on it, which are under the heatsink, on picture i pulled the left one out. Does anybody know what is that? I try to google it but google doesnt know what is it.The resistance is 3,5MOhm.