Usually the bearing in the spindle wore out or laser had died. Nothing you can do with that. I like LG best as they has long lived laser than anything else I had.

Cheers,

Dust gets under the lens and on the mirrors in the laser assembly. Some air compressor method is probably necessary to get the dust out from inside the assembly or at least get disturbed enough that readback becomes possible. Sometimes the lasers have simply burned out...

I was looking into a 54/32/54 (that's what it says...it's an official Compaq part) which was choosing not to read my CD-RW half the time, it only saw part of the files on disc. I thought the lens was dirty.

What I discovered is there is a ballast type thing made of a stack of steel plates in the rear which was askew, because one of the plastic hooks that hold that stack down had snapped off. Also, one of the plastic mounts for the guide rails was cracked apart. I don't really know why. Maybe some 54x antics although I still don't see how disc rotation exerts force on those pieces. Anyway, I then cleaned the lens.

I pushed the plates back into a stack. No obvious way to hold them together and although I have the pieces, no apparent way to glue the plastic back together in a load bearing way.

It works again, I suspect it was the lens.

Marginal reads can sometimes be improved by increasing the laser output. With any luck, there will be a trimpot somewhere on the laser module or the sliding carriage it's built into. I understand this is generally frowned upon, but I lowered the trimpot resistance on my 4X Panasonic CR-581 drive by about 30% and its behavior changed dramatically. Before, I was getting intermittent errors on Taiyo Yuden CD-Rs burned at 8X and could not read modern, generic CD-R media well enough to reliably get the directory contents. Now I managed to copy several hundred megabytes off a generic Verbatim CD-R without signs of the drive slowing down to attempt rereads.

Thanks guys! I'll try the compressor for a deeper cleaning, good tip.

radiounix wrote on 2020-10-01, 20:15:

Marginal reads can sometimes be improved by increasing the laser output. With any luck, there will be a trimpot somewhere on the laser module or the sliding carriage it's built into. I understand this is generally frowned upon, but I lowered the trimpot resistance on my 4X Panasonic CR-581 drive by about 30% and its behavior changed dramatically. Before, I was getting intermittent errors on Taiyo Yuden CD-Rs burned at 8X and could not read modern, generic CD-R media well enough to reliably get the directory contents. Now I managed to copy several hundred megabytes off a generic Verbatim CD-R without signs of the drive slowing down to attempt rereads.

Interesting, just to be clear you're talking about a mechanical pot that would be adjustable with a tiny screwdriver or something like this? I'll reopen a few of my devices and give that a go. Honestly, frowned upon or not at this point they're good for the bin so for me anything is worth a try to extend their life when all else failed.

Yeah. Just a tiny trimpot potentiometer like typically mounted onto a PCB for precision service adjustments. You can measure the resistance with a multimeter. This is a bit of a thing in the console community, where people can't just stick a cheap, generic 52X CD-ROM drive into their 3DO or Sega CD. People do this to improve reads on burned CD "game backups," and I think, to make marginal drives properly read pressed discs. It's not a proper fix, but I've read earlier drives had primitive circuitry with poorer error correction to begin with, and using a higher laser strength could maybe compensate for age-related component drift and minor mechanical misalignments.

The reason not to do this is because if you overshoot, you will destroy the laser. So use a multimeter! And I imagine running increased power will reduce the life of the laser, perhaps sharply. Which doesn't matter if a drive is trash because it's not reading reliably or capable of reading CD-Rs as is.

What I usually do is take the drive apart, lubricate everything that needs it, and clean the lens. I've only fiddled with the power going to a laser diode on a PS2, but those are notorious for their failure rate anyway. I've replaced the laser in a Goldstar 3DO, and while it wasn't actually difficult, it was so tedious and fiddly that I never want to do it again. Mercifully, for game consoles, nearly every system has an optical drive emulator of some variety available for it, or an alternative to loading games from disc at all.
I'm waiting for someone to make a PATA ODE for older desktops that can read disc images from a memory card as CDROMs.