I just buy/use cassette & tape machine replacement belt kits, there's usually 10 or so the right size for CD/DVD players =)

giantclam wrote on 2023-11-04, 07:36:

I just buy/use cassette & tape machine replacement belt kits, there's usually 10 or so the right size for CD/DVD players =) […]
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I just buy/use cassette & tape machine replacement belt kits, there's usually 10 or so the right size for CD/DVD players =)

For the two drives that didn't get fixed, I will. But for the rest, the belt wasn't the problem, gunk on the wheels and the belt was.

non alcohol proof rubber + alcohol = swelling making it even worse 😀
universal belt sets are plentiful and cheap ($3)

Yeah alcohoI and rubber can be a bad mixture, will become brittle fairly quick in time afaik. just looked on ebay and 100 or 150 belt sets for less than a non-working/untested cdrom 🤣

rasz_pl wrote on 2023-11-04, 21:50:

non alcohol proof rubber + alcohol = swelling making it even worse 😀
universal belt sets are plentiful and cheap ($3)

it's not about the price, it's about having to wait about a month for them to get here. Also, it's not just the belts, it's also the wheels.

The drives are doing fine btw.

There's a YouTube channel (NorCal715) that cleans belts and pulleys with acetone. I haven't tried that or boiling belts. I have some drives with the same problem, but they also fail to read discs (one is intermittent, and one reads exactly two discs that I have - any other disc completely hangs the system).

I wonder if the tray rails also need greased, at least on the drive that only reads two discs. It feels a little sticky. I think it's usually white lithium grease, but I've seen someone use silicone grease (meant for plumbing fixtures) on a floppy drive. There's also some green grease that Samsung used in their VCRs, and I don't know what that is.

lti wrote on 2023-11-05, 22:23:

I haven't tried that or boiling belts.

Boiling, by chucking carburetor parts into ultrasonic cleaner without removing rubber gaskets results in swelling - rubber gets bigger and doesnt fit anymore.
Rubber is perishable, no point trying to reanimate when universal set is $3.

I have a bunch of broken optical drives that I have put off dealing with. Sluggish or non-opening drives are pretty much all due to bad belts eh? I've opened a couple up but without really knowing what I was doing I didn't accomplish much. Well, other than discovering a Reggae Hits CD that had gotten stuck under the tray of one "working" ebay drive. Still doesn't work. 👍

A different but applicable thought: Old belt drive turntables. They use a belt but larger and flat, not like an O ring, but more like a large black rubber band. When they stretch there is nothing good you can do but replace, if not the belt will slowly dissolve to some black goop that then must be cleaned up from platter and spindle before replacing. Same can happen to a cdrom belt for a tray. so if you do have a fix with some chemical it will be short lived...just an observation based on nearly ruining a Kenwood KD-2055 because I thought some chem treatment would be ok, and it worth way more than these cdroms. just rambling....

lti wrote on 2023-11-05, 22:23:

There's a YouTube channel (NorCal715) that cleans belts and pulleys with acetone. I haven't tried that or boiling belts. I have some drives with the same problem, but they also fail to read discs (one is intermittent, and one reads exactly two discs that I have - any other disc completely hangs the system).

I wonder if the tray rails also need greased, at least on the drive that only reads two discs. It feels a little sticky. I think it's usually white lithium grease, but I've seen someone use silicone grease (meant for plumbing fixtures) on a floppy drive. There's also some green grease that Samsung used in their VCRs, and I don't know what that is.

Acetone is definitely not good for rubber. Generally it kinda half melts it. Maybe it makes it sticky and grabby again? Not what I'd use, anyway. As far as grease, white lithium grease is good for metal, but not plastic or rubber. It's petroleum based. Silicone or urea-based grease for rubber and plastic. (Be careful, cheaper silicone grease is also petroleum based and not pure silicone)

I volunteer at a repair cafe, and after clogged vacuum cleaners and electric cooking devices with blown thermal fuses, cassette and CD/DVD drives with dud belts are commonest things brought in for repair. It's the rubber disintegrating, replace them and all is well. Messing around with liquids is a temporary kludge at best, at worst risks clogging up bits that still do work.

Some final thoughts on why so many of my optical drives had problems.

The rubber belt slipping may be a point of failure, but may also be a symptom of something else. None of my gear-driven/beltless drives has failed, but they sound quite horrible when opening and closing.

What happens with the belt is that the plasticizer in the rubber leaches out over time and the belt loses its elasticity. It gets harder and also looser. The molecules in the rubber get cross-linked. Heat-treating/annealing the rubber is only a temporary solution because the plasticizer is gone for good, and while you can re-plasticize the rubber, it's usually not worth it. I have belts that have completely hardened and are just stuck in a single shape.

But the optical drive sled itself is another point of failure as it slides over plastic and over time due to grime and dust and plastic wear friction can build up. And when fiction builds up even a good enough belt can start slipping. Replacing the belt will make the issue less pronounced, but I would suggest you clean and lubricate the part where the sled slides over rails. Unsurprisingly, this was the most common problem I had because most of my drives were from 2000s, not 80s and 90s.

A third issue was the gears themselves. Most of the gears are made with good quality plastic, but some were some old ABS and had gotten brittle with broken teeth. Guess it's time to get a 3d printer and start printing gears.

A fourth and most bizarre issue was the wheel and the disk holder getting stuck. Apparently the rubberized material that holds the disk in place behaves differently when losing plasticizers - it turns sticky, like the grommets in old Quantum hard drives. They can be cleared but I'll need to find some grippy tape material to replace them least my disks start slipping in the drive.

Another problem is dirty switch contacts. That might be why one of your drives ejects randomly. I've also seen drives open and then close again.

The gears are usually nylon, and I don't think I've seen a 3D print that was precise or strong enough to replace the original gear. Maybe 3D printing has improved since I was in school, or I never got that printer adjusted properly (I think it had a large nozzle, and it definitely had a warped base, even though the base was glass).

I've only had one drive with a gear-driven tray, and its main controller chip blew up spontaneously one day.

There are also other failures that I haven't tracked down yet. I only have one IDE optical drive that will read discs, and it's a slim (laptop) drive that's starting to get unreliable. I also have one DVD-ROM drive that could read two CDs (one factory-pressed and one CD-RW that has been reused a few times), but it won't read DVDs at all.

This is a good summary of tips for CD ROM repairs. I've got a bunch I've still got to go through, so I've made some notes.

Regarding replacing gears, I wonder if it would be possible to make molds of existing ones and cast replacements?

I'm not going to suggest that everyone start messing with this particular aspect of a drive, but I'll throw this out there just to add some more information on the subject...

Around 15 years ago I had a CD drive that opened fine with a disc in the tray but would get stuck shut when the tray was empty. I had seen this plenty of times but this time I just decided to tear into it to see if a quick fix was possible. I tried the usual cleaning and poking around in the innards of the drive and nothing really made any difference.

Like most drives, this one had a little plastic housing that contained strong magnets in the top of the drive above the spindle. These magnets help to clamp the disc tightly in place and keep it centered while spinning. When there is a disc in the drive, the disc creates a small gap between the metal spindle and the magnets. Without a disc in the drive, the metal part of the spindle that clamps against the magnets is closer to them, so the magnetic force is much harder to overcome.

As an extremely crappy and ill-advised kludge of a repair, I popped the magnets out, wrapped them in a few layers of electrical tape and reinserted them. That created enough of a gap that the drive could then open while empty without any problems. Surprisingly, it also seemed to cause no problems with the functionality of the drive and it never managed to jettison or explode a CD\DVD.

A short time after this I had a friend that was sick of his CD drive not opening when he needed it, but he didn't want to put any money into the system since he wanted a new one (it was probably 8 years old). So I told him I knew of a quick band-aid kludge that could work as a temporary fix if he was willing to accept the risk of it possibly chucking a CD into places it doesn't belong. He accepted, I did it in 5-10 minutes and from what I recall the drive continued to work just fine for at least another year or two until I helped him get a newer PC.

So, yeah... it totally worked, but don't do what I did... use the steps in this thread to fix your drive properly if it won't open. 😒

EDIT: Oh wow! A guy in this reddit post makes an excellent point regarding this. I will quote it in case it gets deleted:
https://www.reddit.com/r/retrobattlestations/ … that_wont_open/
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GabrielZ666
4y ago

This problem is usually caused by the drives being closed for a long time, causing the magnets in the motor tray to stick very tightly to the part that holds the CD once it is in place. Many times it has nothing to do with the belts, what I personally do is try to demagnetize those pieces with the tip of a screwdriver, just by passing it over and over again over the magnets, this way they "lose strength" and the tray opens easily. Give it a try and tell me your results!

GabrielZ666
4y ago

Oh and you can test this easy just by putting a CD! With a CD in place, the gap between the magnet and the holder piece is not that close so the tray should open with no effort. Now I think this would be a good way to avoid this, storing the drive with a CD inside to prevent this "magnet fuse" xD!
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He seems to suggest partially demagnetizing the magnets themselves, which I wouldn't recommend... Still, this is an interesting point and is something I hadn't considered before. If a drive isn't used frequently (which, let's face it, few have been in the last 20 years), I guess the metal part of the spindle could become magnetized by being in close proximity to strong magnets for a extended periods of time. I will definitely try demagnetizing the top of the spindle the next time I find a drive that sticks shut. I have a whole file cabinet drawer full of CD drives, so I'm sure I've got at least one that is sticking. I will report back here with my findings if I get a chance to test it.

I also have a couple of drives that experience intermittent issues with stuck trays, and like everyone says - it seems much easier to open with the disk inside.
I always thought it is an alignment issue, never consider that it could be due to the magnets. Will keep this in mind, maybe try the demagnetizing screwdriver trick next time something like this bothers me.

In some cases it can be the belt. I once fixed a stuck tray DVD drive by replacing its worn belt with a good belt from a bad laser DVD drive.