Hello everyone, I have recently gotten a bit nostalgic about the stereo equipment I grew up on and have aquired a Yamaha CA 610 II amp and CT 810 tuner (both working), a Nakamichi RX 202 Tape deck (needs a little help) and a Denon DP 47f TT (Working). I Purchased a Yamaha A 1020 Amp that turned out to be DOA and I also have a Yamaha CA 1000 that needs help. I am interested in learning how to repair these units. I have started reading an eloctronics book and I have a fluke DMM, Tektronix 466 100 mhz oscilloscope and I have made a dim bulb tester. I am currently focusing on the Yamaha A 1020 Amp, I found 4 bad transistors, all on one side of the heatsink, 2 npn and 2 pnp. I replaced these transistors with the same part number toshiba transistors. I used the dim bulb tester (checked it using a working amp) and after a few seconds the light did not dim so I removed power. I rechecked the transistors and they still appear to be good. I guess I should mention that when I received the amp the power light came on but no sound from speakers. The relay did not pull in and a bank of resistors was generating alot of heat, also the fuses still show continuity. I have downloaded a service manual for this unit. Any help would be greatly appreciated