• Hello, Guest! Welcome back, and be sure to check out this post for more info about the recent service interruption and migration.

iMac (Summer 2001) optical drive replacement

Alex

Well-known member
Quick update

The belts arrived but I foresee some challenges with resolving this with only a new belt because the roller appears to spin independently of the shaft, this as per what I had documented above. I will confirm this and report back. 

I have some explaining to do …

Sorry for not providing an update yet. Truth be told, since the COVID19 outbreak everyone is at home and I have had to spend a lot of time with my 6.5 year old daughter. Schools across our country will remain closed until 09/2020. I've also used up all my spare time getting up to speed with my website. Despite this I will be going through this post to remember my steps and see to it that I take some photos and document my process as carefully as I can.

I will likely post a link here to nichrome.us where I blog my Mac adventures. Sadly it might be a real challenge to post anything directly here because I can't seem to upload any more images due to having reached some data quota on attachments which frustrates the process of using images to document steps and so on. I have contacted the admin here but never got a response.

Until then, stay safe everyone, meaning stay inside as much as possible, disinfect and please wear a mask to protect yourself and others.

 
Last edited by a moderator:

Alex

Well-known member
One more quick note

The rubber roller is loose, turning independent of the shaft so I will have to fix this as well.

View attachment 31079
Today I took the machine apart again.

Firstly I noticed that the replacement drive belts I received from China were slightly thinner and were much more rubbery, softer, not sure how to put it. Now, I didn't yet replacement the best because the roller, pictured above was not spinning with the inner shaft. In other words, the rubber rollers wouldn't spin so no CD was ever going to come out, with or without a new belt.

What I did was remove the section that holds the roller and cleaned the heck out of it, warm water and detergent then a 15 minute bath in enough isopropyl alcohol cleaner. As it remained submerged I agitated the rubber rollers, sliding them on the metal shaft to get it clean underneath. This made no difference so I got some thin double sided tape, pulled back one side of the rubber roller and then wrapped a small amount of double sided tape without overlapping it on to itself. I applied double sided tape to both sides of the roller.

I then reassembled the computer and discs only manage to peek out a little, they fail to eject still.

I have to change the belt now but these replacements seem rather soft but maybe they can apply enough tension. I also need to ensure any and all line is completely cleaned off from the mechanics that drive the belt or it might slip but the rubber roller is indeed spinning with the shaft it is slid over.

I wish I could power the drive while it is disassembled so that I can test it without having to reassemble the whole computer each time. I really need to isolate the issue if it failed to eject again. I can certainly here the motor work inside the Mac. The optical drive reads discs just fine too.

Any advice on this?

 

JDW

Well-known member
Hi, Alex.

We would need a pin-out description of the power connector on your drive to be sure the power requirements, but most all DVD and CD drives require both 5V and 12V.  You could technically wire a 5V battery and 12V battery to your drive to satisfy those power requirements, but finding a 5V battery is the problem.  Maybe 3 AA batteries in series to make 4.5V might work, assuming you also have a 12V battery to drive the motor mechanism.  But the also assumes no crossed wire mistakes on your part.  Fused wires would be safer, but now we're getting more complicated.

There are ways to use only a 12V battery (since you lack a dedicated power supply unit) to generate 5V too, but that requires a voltage regulator and a couple capacitors.  Those parts are cheap and easy to buy on Mouser if you don't mind the shipping charges, but again, that is making this more complicated that merely doing what you are doing now.

All said, you are looking for something to make your job easier, but finding the right 5V and 12V power sources add a level of complexity that you probably want to avoid.  Finding a way to extend the cable would seem to be the best course of action, but that would require parts and wires you probably don't have.  Someone else like @Bolle might have a better idea though.

 

Alex

Well-known member
@JDW thank you for your reply and advice. I sincerely appreciate it. It sound complicated even though you explained it very well. I simply lack the background knowledge and experience take your comments forward to a practical set up. I may just work around the issue by reducing the hard disk/optical cage by removing the HD leaving the optical drive casing removed if possible. This will potentially allow me to view the drive in motion. Even without an OS the optical drive should inject and eject by its own devices, at least I hope so and perhaps this will allow me enough visibility to see the mechanics of the drive work.

It may also be that the drive does indeed need the new belt in place, something I thought I could avoid for now. I also believe that the little wheels that the belt wraps around might be contaminated with some lob causing the belt to slip.

I will keep folks updated because I know that there is interest for others.

Thanks again for your time and expert advice!

Sincerely

—Alex

 

Alex

Well-known member
lob, I meant lubricant.

I replied to your message first thing in the morning hence the typos and what nots.

 

Alex

Well-known member
So I have the drive mechanism open again. I am manually moving the gears to simulate disc insertion and ejection. The robber roller and the old belt are very good at gripping the disc, the problem actually is strongly pointing to the magnetic ring. It appears to be a barrier of entry and exit for the disc. For entry the magnetic ring is not as contentious because on can gently push on the disc but on exit it's more complicated as only a small sliver of the disc protrudes past the iMac's disc insertion/exit slot and because ejection is unsuccessful after a few seconds the drive injects it again.

I did try an external adapter meant to power a bare SATA/IED HDD drive as it has a molex power end on it but it fails to power up the drives in their chassis. The optical drive has no such molex connector so what I may do is plug it into the Mac via it's own native cables and see if I can view and insert eject.

I will keep you all posted.

I am taking photos along the way so I will eventually create a blog post detailing my steps but for now I will use replies as a form of note keeping and status updates.

 
Last edited by a moderator:

LaPorta

Well-known member
If you get this going, I am certain it will be of great use to all of us. I don’t think there is any such guide floating around.

 

Trash80toHP_Mini

NIGHT STALKER
What connector is on the back of the drive? There are inexpensive USB adapters available for just about any internal peripheral be they desktop of laptop.

For testing, turn it into a bare nekkid external USB optical drive. [}:)]

 

Alex

Well-known member
So here is the latest.

I tried and tried and I've given up hope. This does not mean it can't be done. It just means that in my case there is something about the roller that won't grip the disc hard enough. I've cleaned the rubber roller to an extreme and added thin but very strong double sided to tape to ensure the rubber rollers rotate with the shaft and they absolutely did so but there just isn't enough grip or something else.

I took apart all the drive's mechanics and gears, applied new grease to gears added more double sided tape under the rubber roller but some slippage always remained.

I haven't given up completely I suppose but for the time being I have gotten tired of the disassembly/reassembly process, which has been about 8 times in all.

So for now I am leaving this but if and when I come back to it I will come back here to post any more info.

I am not sure if I will post this on my blog because it wasn't a success but instead a learning experience on  the disassembly/reassembly of this poor little optical drive.

 

JDW

Well-known member
I feel your pain quite literally Alex, as I now have two 400K floppy drives and a 512K motherboard in need of repair help:





Sorrow never ends. :-(  

 

D@llas

Member
I had good success following this guide on-line, with some modifications:

https://imgur.com/gallery/hecBMSW

Instead of microwaving the belt (wife absolutely forbid it), I boiled water in a pot and put the belt on a small strainer so that it was suspended about 1/3 from the top. Let boil for 10-15 minutes

Follow the rest of the directions on the page.  Clean the black roller and make it semi tacky.

After removing the belt, i gave it a VERY quick spray shot of Loctite spray adhesive.  Just enough to make it a little tacky as well.

Drive works almost like new.  I'll make sure and use it frequently over the next few days to make sure nothing actually got glued and stuck.

IMG_9801.jpg

IMG_9804.jpg



View attachment IMG_9802.m4v



View attachment IMG_9803.m4v
 
Top