So, I found a CLD-M90 $9.99 at Goodwill. I can't resist a $10 LD player, first LD player score in months of searching. Brought it home and put it through it's paces, tested a bunch of LD's, worked out the mech on 5 disc carousel, the thing is super cool in that regard. Listened to some tunes, watched a couple flicks on it, and fell asleep with it running. Operation seemed solid. This morning I went to eject the disc, and got no response. Turned it off, no mech noise. Turned it on, hit eject, nothing happens, hit play, nothing happens. It's not throwing any errors, video output is working, the LCD display works, it reacts to button presses, but no response at all inside the player.

I think that 5 disc 'super cool' autochanger mechanism was its downfall.
Still by the sound of it you got $10 worth of usage but I'd expect at least an error code if it doesn't function correctly.

The M-90 won't give codes. I can't remember off the top of my head if this power supply has the ICP fuses that will open if there's excessive current draw (like the load motor).
And yes, the multi CD change mech (swing arm) was a major downfall on the "M" series players.

Do you know if the mechanism was based on any of Pioneer's industrial changers or jukeboxes, or was it a completely consumer design?

I always thought it was odd that Pioneer came out with the M line changers because they were clearly not ready for PrimeTime.

Thanks for the help fellas, I'll check for fuses. It was an excellent machine for $10 while it worked, it was very clean and looked to be taken care of. Mechs on these make some noise, but it was working flawlessly last night, without a hiccup. I really put it through it's paces, was sure I had a keeper.

The mechanics are based on entry level single side players of the same vintage. The only "fancy" part is the swing assembly for the multi CD pickup. I guess they just figured multi CD play was wanted by the market place. It probably would've been an engineering nightmare to use a carousel tray...

This guy has 4 fuses, 2x3A and 2x1A they all looked fine, pulled them wiped them off and replaced them, player starts up as it did before. I thought about just jumping them, but I'll hold off. I didn't see any other fuses. I've been messing a bit with it, looking for anything burnt, smelling around if something warmed up, maybe something just gave out? Seems really odd that it would go from normal operation to unresponsive. I'll dig and see if I can find the service manual, bust out the multimeter.

Let me know if you find a service manual, as a CLD-M90 is my first LD Player and I too had one from a Salvation Army.

Guess its a matter of time I'll run into your problem.

Hopefully you won't, I haven't located service manual for free download anywhere, they do have it for purchase in PDF form anywhere from $5-$10, which I don't think is bad if the sites are legit and they don't run off with my CC #'s. Not sure how much it would help, I don't have any experience diagnosing LD players. Without a code, I'm not positive what to think. I'm hoping the service manual would help me with that. I don't know how the system starts or how/if it checks itself and throws errors. Like if the laser or one of the 12 motors goes down, does it just stop functioning? I can't even narrow it down hardware wise, maybe I can track something down with the multimeter.

What I do know is that I fell asleep and when I woke up the LD player was still on, the movie had finished playing and the player had parked itself as I think it would normally when a disc was finished. I hit eject and complete silence, it just doesn't make sense to me, if it was go out in a blaze of glory, I think it would have done it while I was really working it out.

I haven't had time to dig into it much but I've figured the fuses aren't the culprit, I tested them, rearranged them in the holders a few times (by amps), and even jumped the holders on the PSU, and it does the same thing as it does w/fuses. :/

For $10, I should just let it go, but I can't make it any worse, if I kill it more, so what. Worse thing that happens is it ends up in the trash, best thing, I learn something new. Finally finding a player in the wild felt too good, and even though it's an M90, it is very very clean inside and out.