How do I turn off optical on my accurian 5048? Hooked it up and powered on and keeps flashing optical

SOURCE: Accurian AVR 31-5048 6.1

I power on the reciever and then it reads PROTECTION and then powers off. I initially thought that I blew out the reciever but I was wondering if it was as simple as a fuse. I can locate the product manual for this reciever.

SOURCE: How to overcome

Probably need to replace output transistors and a resistor or two. Could also be one of the 12v regulators.

A job for a tech not for the average do it yourselfer.

Repair cost around $100-120