So if you've tried other ac adapters with the same voltage / polarity requirements and still did not power up, then there are a couple of components on the power cct that could, perhaps have blown. I see a diode D2 (SR1K-2) and a pwr transistor or FET (Q1 listed as B744 or B731), I can't find it on the parts list. But you would have to go in with a voltmeter to see whats going on on the power rails at those points.