I have a SGC MAC 200 that is generating hash at several points across each band. I got this used so don't know its history. I am sure it is the tuner because I can remove power and the hash noise goes away. This noise is a loud hissing noise that shows up at intervals when tuning across the band. The most likely cause is the microprocessor.

Has anyone else experienced this or know what to check. I don't see any obvious damage on the board. Due to the high cost of SGC service I have to fix it myself.

73
James
N5ARW