Repair a Sony SCD 777ES?

Check with Sony in Laredo, Texas. They are out of some of the parts for this player because the parts are no longer manufactured.

Junk it! It needs serious restoration apart from the immediate issue. Not worth the money.

I would look for a Sony repair facility. They will do a great job of returning your CD player to factory specs. Providing they have the parts, as Stereo5 mentioned.

I have read plenty of negative stories about the current situation with Sony repair.
It is totally outsourced now. And not very good either from reports.
My own Sony repair horror story was rather negative too. So i just accept they suck.

Flip a coin. Those are your chances of a satisfactory service trip to Sony in Laredo, Texas.
I sent them my 777 in it's original box.
The first thing they do is recycle your box. Then they fix the player on a flat rate schedule.
My player came back to Phoenix in a single box, with the heavy CD puck in a plastic bag, duct taped to the top of the player, with one piece of duct tape. This allowed the puck to slap against the surface of the player, marring it.
And, most importantly, the player still wouldn't play CDs or SACDs.
I had to wait for a Sony tech to call me (in a 2 day window) before I could get an RA # from Sony.
The biggest insult came next. The tech said every piece is thoroughly tested before it is shipped. I actually had to return the player with (1 each) non playing CD & SACD.
He said it was probably my discs. Yeah, right!
The player came back, this time with a new transport. Since I had already paid $220.00, the 2nd repair was "free".
Sony had my player tied up for over a month. When I questioned why my original box disappeared, they said this point is clearly stated in their FAQ section.
I immediately sold the player, and sold my XA7ES a year or 2 later. I'll never buy another Sony player.