Other Nakamichi Repairs
Nakamichi 630 Preamp\Tuner
The unit appeared dead but looking closely I could see one of the tuning lights was very dim. Checking the regulated supplies on the PSU board they were all low (6.5V) as was the a\c to the board. The mains transformer turned out to be faulty and the mains input to the primary had been rewired at some time, replacing the mains transformer with a 15V-0-15V one sorted it.