Nikko Amplifier Repairs

Nikko Alpha 130 Stereo Power Amplifier

This was in protection, looking inside there didn't seem any damage but.. the output transistors in the left channel were short circuit (not a good sign), along with the TO220 drivers and some of the TO92 transistors. I replaced them but it still wouldn't work correctly. The output emitter resistors were open circuit. The cause of this mayhem could have been as this is a 220V AC model the secondary voltages were way too high for correct operation, the 8 ohm setting was 67V +\- instead of 59V +\-, there were burn marks on the PCB near the output transistors, so must have been over-heating for a while.