'PROTECT' MSG EVERYTIME TRYING TO OPERATE

This appears to be a very common problem here on the board. It means the unit has shut off the outputs because of either a bad speaker or shorted wire, or some failed part in the amplifier. If the trouble continues after you disconnect the speakers, the unit will require service to diagnose and replace the failed part(s).

I've never worked on this model, but in many brands the amplifier integrated circuit is a common failure. They are often not properly mounted for efficient cooling and burn themselves out. Another typical failure is some power supply part that is under-rated and just goes bad, and this is showing up as the protect failure.

Without a diagram and no direct experience, I can't suggest any specific action you could take, other than checking with a local shop for a repair estimate. (You might try contacting JVC on their website or by phone to see if they have any service bulletins. If something becomes a chronic issue, the manufacturer sometimes extends warranty service to cover the repair. Never hurts to ask!)