I have a NAD 2200 PE that I am repairing/upgrading. When I got it the right channel had a number of fried resistors, and three output transistors (Q320,Q318,Q314) and R368- the emitter resistors were fried and the main PS caps were bulging. I have recapped the unit, and replaced the output transistors (I had some spare originals that I had pulled form another 2200, replaced all the fried transistors and any that looked that they have heat damage, and also replaced Q302/Q304 and Q306/Q308 as although they were of on the transistor tester I thought it better to replace them. I have also replaced SR 302. The rest of the transistors test ok on the right channel and the unit fires up and comes out of protection, and both channels pass signal. However, these units on idle (no input no speakers connected) should draw 0.4A approx. This unit starts there and then creeps (in small jumps to towards 0.75A- which is when I noticed a "warm" smell- and turned it off. I use a Senore PR57- which does not have current limiting. I tested the NAD with cold bias (Collector Q302 to collector Q304) to see if it was the output transistors, and the result is the same- the current creeps up. So although I have "fixed" the unit, I don not think I have found the underlying cause as to why the right channel self destructed. any thoughts or guidance would be greatly appreciated Peter