Repair for Nakamichi PA-7

[tehach12]

Hi, anyone have any suggestions for a repair shop in the SoCal area for my ailing Nakamichi PA-7? It still works, but occasionally pops frightenly loud through one channel without any warning but usually when it's cold.

Someone told me its probably a capacitor going bad but I know that troubleshooting and repairing it professionally are beyond my abilities.

Thanks