Hi all-

This is my first post here, but I have 40+ years of on-and-off experience with Laser Discs and players going back to the Discovision and Magnavision rollout.

My current issue is in a Pioneer CLD-D604, that I bought in maybe 2011-2014 in unknown condition. The '604 originally worked after I cleaned its belt, but sometimes it would not play a disc unless I pressed the Side B key during loading. Then a while back, it would not eject the disc inside and displayed the E3 error. I let it sit until this week, now I have started to work on it. I saw the carriage (or pickup, or slider?) motor mentioned in this topic:

[CLD-D515] E3 Error

Reading that, I noticed that the gear that meshes with the motor worm gear would spin when I first turn the player on, but it was not meshing with the other gear, that meshes with the toothed track to move the pickup assembly. I also noticed that the gear against the worm gear can "tilt" into different angles. Then I read this topic:

[CLD-D504] Repair question

It mentions the "M holder", and apparently failure of this part is common enough that a replacement has been made available on Ebay, very nicely. It sure seems that I need this part, but I would like to get confirmation or any other comments from members here. Also, the Ebay part includes instructions but not likely for how to get the disc out of my player first, so if you have tips or a procedure to follow for that, I appreciate your advice.

I have not yet gone through this forum much, so if all of this has been covered and answered before in a "sticky" topic, I apologize for the duplication. Thanks!

I figured out the first step by removing the cover from my CLD-D504. The laser pickup should be resting under the tray, not above the disc. So, I need to figure out how to achieve that next.

There are a bunch of M holders out there, some are 3d printed and may or may not be great, I don't have any players but have heard stuff
so be careful on those.

I think if you have the one issue you may need to move the worm gear back to get the laser back into position?
I have read posts about that, so make sure that is your issues before you try it and fix it.
I'm no tech just trying to remember what I've read.
Good luck.

Edit: I don't have any players that use M-holders I have LD players

Thank you for your notes, rein-o. I need to get my pickup assembly moved under the disc tray before I can proceed with the disc removal and tray ejection, but after that, the M holder swap looks easier than I expected, from the Youtube video that the Ebay supplier (thelaserparts) has made.

I got the pickup assembly moved under the disc tray. Because of the loose gear, it just took a combination of gentle jiggling and some worm-gear turning to get it into the side-turn area, then under the disc.

After that, lowering and opening the tray and removing the disc was easy, just a bunch of manually turning the pulley that has the belt on it (clockwise as seen from above, achieved by rolling the accessible side of the pulley toward the back of the machine). Next is the pickup removal and inspection.

This player had a physically hard and dirty life before I got it (and I only paid maybe US$15 for it), so I think I should do an extensive cleaning of its interior and careful cleaning/relubrication of all of the moving parts and paths before I reinstall the pickup.

From prior experience with dirty electronics, I would get it working first before going into cleaning.
Unless its that dirty, but you could be spending more time cleaning and then never even be able to repair.

Thanks, rein-o. The player did work well (other than the occasional side A/B issues as mentioned above) until the stuck-disc event. My thoughts about cleaning are mainly related to whether dirt could be in the tray/pickup paths such that the motors/M mount and belt get more stress than they need to. I have cleaned and relubricated VCR loading and transport mechanisms before, so this should not be too difficult.

My M holder is indeed broken. Zero-for-two on gear posts. This project is less urgent now because I fixed my CLD-D704 (thanks to the notes from krbahr) and I also tested my PR-8210 and it works fine too. But, it will be nice to get this machine working as my full-function backup.

I received my M holder from thelaserparts and it fits fine. I did some internal cleaning and lubrication, and I had to replace the belt as well. Now the player works fine except that I found one disc so far that gives me an F5 error (focus problem at startup) on side B, regardless of which side is "side B" (face up). I will work on that issue some time in the future, since this is a backup player and I have lots of other projects going on here as well.

There was some dirt on the gears and the paths of the pickup which I cleaned, but I found out why the dirt got inside. There is a plastic cover on the back over the side-change mechanism end, and that cover has a gap at its top edge between the cover and the main metal cover for the player. I decided to use some good-quality electrical tape (Scotch type 33) to cover that gap, as shown in the attached picture. CLD-D504 players and maybe others could have the same problem, but CLD-D704s have a metal extension of the main cover that avoids this issue.

You could also have the rubber pad wearing out.
Again there are some floating around that are slightly thicker, I think blam posted about this.
They work for the LD but may be too thick for CD or DVD playback if your player plays DVDs.

Thanks, rein-o. If the "rubber pad" is the same as the "grip ring" (original Pioneer part #VEB1237), I did also buy one of those from thelaserparts. I did not install in on this machine yet, though, because the existing ring does seem to be behaving properly. I can do tasks such as switch from side A to side B (while side A was at high speed, near its beginning) and watch the player quickly stop and reverse a 12-inch disc without any obvious indication of slipping. The ring on this CLD-D604 is a white or very light gray color; I do not know if some rings are better than others. I have only had that one disc have a problem on side B so far (and it is the one that lost a label on one side as I mentioned in another topic).

My intent, once I decide to get into this player again, is to hang an oscilloscope on the test points/signals for side A and then compare them to the ones for side B. If I am lucky, it will just need minor adjustment.

Yes grip ring, loss of words at the time of my last post