[updated topic] Broken laser sled gear

[OldRover]

I received a broken CDROM unit in one of the lots I pulled in awhile back and figured I'd see if I could get it running. The drive receives power, so I know that the power is correct. The LED array fires up as normal, the 7805 has correct voltage output. However, the drive motor doesn't spin and the laser sled doesn't move. The motor coils are intact, so I know it's not a broken motor. My best guess is that it's the drive controller circuit. Unfortunately, I have no idea where this is on the board. Any leads or information would be greatly appreciated.

[nat]

Did you verify the laser is working? If the laser is dead the motor won't spin and the sled won't move.

[OldRover]

When the laser is instructed to move, 2.00 volts are applied to its circuit. However, it fails to move. The laser sled motor appears to be fine electrically though; the motor coils are intact. It might be that the motor has issues inside of it. I did try lubricating the gears earlier, but that didn't seem to help at all. But as for the laser itself, I'm not quite sure how to verify that it's functional, I can only test the motors and expected circuits for power. How can I verify the laser itself is functional?

[OldRover]

I've found one potentially large problem in the drive. The small gear that sits between the laser sled motor and the sled rotor is toasted. Completely. I believe this particular issue has come up on the forum before...

[OldRover]

It seems that this could very well be the problem. That compound gear is completely destroyed and was stuck. The plastic is really crappy, heh. Replacing it is going to be next to impossible though...finding a compound gear of that particular ratio is going to be a friggin nightmare.

Anyways, I did verify that the laser sled motor itself was functional. I removed it from the assembly and powered up the drive, and the motor came to life, spinning like nobody's business. But now, I have no idea how to get this gear out of the assembly.

[nat]

Looks like you tracked down the problem. This is the second most common issue with these drives after the optical unit itself.

If you are able to find a replacement for that gear, please let me know. As of now it's unknown where to find a suitable substitute and the "broken gear syndrome" has historically been an unfixable complication.

[OldRover]

Mike pointed me in the direction of a company that reverse engineers gears and can make new ones. As of right now, that seems to be the only option. But this seems like it might be a stock gear, so it's just a matter of tracking down the type. I'm still at a loss for how to get the gear out of the assembly without destroying it though, although I may just do that anyways since it's completely hosed.

The drive's electronics seem to be intact, so this is probably the only actual issue. The chip that runs the motors appears to be IC102 (CXA1082BQ), but it appears to be fine.

[OldRover]

I've been able to extract the compound gear from the assembly, and am going to be sending it off to the gear shop tomorrow. With any luck, they can remanufacture this gear and we can start reviving old CDROMs that have this same problem.

[nat]

Did you figure out how to remove the gear without breaking it/anything else?

[OldRover]

Yeah but it wasn't easy. There's a small black clip that holds it in place, but it just pops off rather easy. The gear was already ruined but still has enough teeth...they should be able to fill in the gaps with their machine. I dunno where the black clip flew off to though...but fortunately, the post is a pretty standard size and can be clipped again with ease. Even if the right clip can't be found, a workaround can always be used, such as a piece of thin, sturdy wire curved to the correct size. In any event, there's the possibility that this is a stock gear...in that case, it should be quite cheap to replace. If they have to custom-make this gear, then it's going to get expensive quickly. But considering how rare these CDROMs are getting, not to mention the fact that they've been out of production for well over a decade and a half, any price to keep them alive is worth it...in my opinion anyways.

[CrackTiger]

I hope that this problem can be fixed and is worthwhile to do. It sounds exactly like the problem one of my Turbo Duos has.