Internal Error - Yamaha RX-V671 7.1 Channel Receiver with an Identity Crisis

***Note - the programming method used here does NOT work for newer Yamaha receivers. They changed the programming method since this receiver was made, and I don&know what they do these days.*** Not too long ago, I finally figured out why the old Sony 5.1 channel receiver wasn&putting out audio. This made me want to try another one, so I found this here Yamaha receiver for $20 on the Bay of E and immediately got curious about what was wrong with it. All it does is display "internal error" when plugged in. Is this one going to be as easy a fix as I think it will be? Camera gear I use: Nikon D800, Nikon Z50, iPhone XS Max & 13 Pro Max, DJI Action 3, Autel Evo Nano+, Autel Evo Lite+, DJI Mini 3 Pro