Apple CD SC ejects discs

[CelGen]

So I finally found an Apple CD SC 1X CD drive to finish off my stack of external Macintosh II peripherials but this one is giving me trouble.

I have not hooked it up to any mac yet but if I put an audio cd in a caddy and put that in the drive it accepts it, sits there for a few moments and then spits it out again. I looked more closely with a flashlight and the drive is not even spinning up the disc but it sounds like the laser pickup is trying to do something.

All I can think of is a hooped motor driver. Any ideas?

 

[Osgeld]

clean and lube it

 

[CelGen]

What is there to lube? the spindle motor itself spins freely and the caddy seems to be properly loading and ejecting.

 

[LCGuy]

These drives usually do that when either the power supply is on its way out, or if the laser intensity needs to be adjusted. The first thing I'd try and do would be to adjust the laser intensity. If you can open the drive there should be a pot on the laser assembly that you can adjust with a screwdriver that will allow you to adjust the laser intensity.

 

[CelGen]

There are a couple of adjustment pots. Any idea which one it is?

I'm about to try powering it off a different PSU and see what happens.

 

[Scott Baret]

Just a thought, but have you tried another caddy?

 

[CelGen]

Several.

I'm still suspecting the driver for the spindle motor or something in that circuit. The disc won't spin up at all. It does not even try.

 

[bear]

Don't play with the adjustment pots until you clean the optics. I used 99% isopropyl and a lint-free swab. The lens itself is probably relatively clean, but is easiest to get to. If you take the cover off, you'll basically be staring right at it. Clean it, and if the problem persists, carefully remove the plastic assembly containing the lens, and clean off the prism underneath (you'll see it; it bends the laser beam 90° up through the lens you just removed). The surfaces which face upwards are most likely to need cleaning, but clean them all while you're in there (including the one which faces the laser).

This cured mine of the exact same problem. IIRC mine didn't spin either; the laser assembly does a focus cycle to figure out if there's a disc first. If the optics are dirty it can't focus on the disc, assumes it's a transport error, and ejects the disc.

 

[mcdermd]

Thread revival!

CelGen, did you ever get any fix on your CD SC? I have one that is pulling disc in, the spindle motor spins up three times and the laser moves but it then spits it out. I have cleaned the lens and the prism but no changes.

One interesting note is that if the drive is flat, it sounds almost off-balance but tilting it makes the rotation "smooth out".

Ant one with any ideas? Replacing the drive isn't as simple as swapping for another caddy-load drive.

EDIT: This may be an issue:

A loose spindle table may also result in continued spinning upon eject orsluggish or noisy startup or seek since the if the spindle is loose, the

motor will not be able to properly control disc speed during speed changes.

 

[mcdermd]

I solved this in a ham-fisted sort of way. I put a 2x Toshiba XM-3401TA caddy-load drive in instead. It is working with the Mac OS 7.6 "universal" CD ROM driver. It took some hacking up of the Toshiba drive to connect to the CD SC's eject button, LEDs, audio outputs, etc but the original CD SC case is untouched so if I ever do get a working Sony drive to put in, nothing will be out of place. Most importantly, it looks entirely original from the exterior.

 

[CelGen]

I never did manage to get it to spin again however after my last post I played with it for a few more days then put it in storage because I moved. Now that I have the IIfx and all the parts to make the Purely Macintosh System I will probably be pulling it out again. I can also start poking around with an oscilloscope I previously did not have.

 

[techknight]

you either have leaking caps, or the optical pickup unit is toast. The disc usually doesnt spin if the PSD (position sensitive device) pickup cannot see the beam. if it spins and stops, it sees the beam, but it cannot see the proper levels to keep the PLL locked. either way, its a bad pickup unit. The high frequency whirring/hissing you hear comming from CD drives, and CD players is the loop noise from the PLL servo loops keeping the speed/positioning locked. If you have been working on CD players as long as I have, sometimes you can "listen" to these screams the drive makes to determine whether the PLLs are working on either extreme of the lock range.

 

[CelGen]

I want to further poke at the motor and see if it's not the caps affecting the driver.

An oscilloscope can be quite handy now,

 

[techknight]

when in doubt, change the caps.

 

[CelGen]

BuMP.

As a follow-up and to close the thread, I got it working.

I spent the day helping a friend get a caddy loading Plextor CD-RW drive that someone had installed in a NeXT Cube. It had the same issue. Turns out that a simple blow-out of the drive didn't help because the dust that had been sucked in through the open front of the drive had stuck to everything, even the lens. You had to dismantle and clean the lens with a Q-tip and rubbing alcohol to get it to work again.

I tried the same on my CD SC and it worked there too! Apparently this type of drive needs to sense a reflective surface before it will try to spin. The dust was blocking the path so it always thought no disc was in the caddy and just ejected it.

 

[bear]

you're welcome. (@;

 

[techknight]

hell, i figured that was the first thing you had tried was clean the lense. its an automatic thing for me, i just assume it is for everyone else.

 

[Trash80toHP_Mini]

Crap-doodle! Now you guys have guilted me into feeling like I need to at least try to fix mine before relegating it to ATOMization.

 

[CelGen]

hell, i figured that was the first thing you had tried was clean the lens. its an automatic thing for me, i just assume it is for everyone else.

It sucks to take the top off the CD SC. There's a PCB with about a dozen connectors running to it and as you pry the thing apart you have to unplug everything along the way. It's a lot of work that I really didn't want to do.