AIWA CX-NA777 CD Repair, please help!!

[lerasium_burner]

Okay so I am completely new to electronics, but I am a professional Home Contractor with lots of experience fixing things in general. Recently I decided to try to fix up a stereo for my shop, and so I went and salvaged an AIWA CX-NA777 Stereo system that worked decently except for the CD function. I've taken the panels off the top back and side so I have full access to the inner guts of the machine, and from what I can tell, the problems stem mostly from nonworking motor/belt drives.
The 3-CD tray has problems rotating between the trays, unless I give it the lightest tap in the right direction, then it rotates fine. In addition the main tray that slides in and out of the stereo has problems moving unless I help it, and I can see the motors for both of these things rotating but the resistance is too much from the gear or the belts are not tight enough or something. Next, the CD laser scanner thing that actuates up and then down as the tray rotates needs help to go up and down. Lastly if I put a CD into a slot, help the tray slide in, help the rotating tray spin to the right disc number, and help the scanner move up to the CD, it will play 1-3 seconds of audio then skip backwards and replay. Im sorry if none of this makes sense, again I have little experience with electronics, but if anybody has idea of what this problem may be or even where to start fixing it please respond. Ask questions if needed, I will do my best to answer them,
Thank You,
W

 

[Rich D.]

Sounds like every bit of mechanical movements are degraded!

Since you say all the other movements need a bit of a shove, I think the stepper movement that moves the LASER in and out across the surface of the disc is also sticking. That would cause the electronics to continue to play the same seconds of audio over and over. It can't move to the next band of bits further out the disc and therefore keeps reading the same chunk of audio data over and over. Apparently it moves enough to read the table of contents, and it might even be able to move enough to find another track, but a single tick of the motor might not be enough to break the friction.

If you really think it's worth the effort, I would work on the mechanicals first, you might find the electronics are all working and the mechanical failures are making them look bad.

 

[jpanhalt]

Agree with Rich D. Sounds mechanical -- gummed up capstans and other mechanisms (maybe a limit switch?). I've fixed some old stuff by careful cleaning. Then re-oiling with plastic safe lubricant (if applicable) or watch oil, not WD40. The worst thing I have found is a split plastic gear or broken cam/lever Even the gear can sometimes be salvaged. A cam/lever is more difficult.

Once the mechanical get working, then look at the replay problem if it still exists.