Chapter 10: About the CD Drive

Ok, here whe go. Between writing the previous part and now It's been two weeks. And a lot of stuff happened.

Initially I thought I could fix the drive, so I started to take it apart. Since it's from the "replace the whole assembly"-time of retro tech there wasn't a service manual available.

Quickly I learned three things:

To get meaningful access to the PCB and mechanical parts, I needed to desolder the tray motor.

The decoration plate on the front of the tray can slide up and away and has to be removed before the front bezel.

Old plastic is brittle.

// I knew that, but a reminder is always welcome. //

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The bottom of a large PCB showing only traces and vias.

The decorative front of a cd drive tray broken in two.

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Because I already broke a part of the drive before even doing anything I figured it's worth to check eBay to see if I can get a replacement unit instead. And as luck would have it, there was one listing for a tested working

// HP-MATSUSHITA CR-583-B //

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drive for 35?. So I decided to leave the broken drive alone and just replace it.

When the drive arrived a few days later, I was a bit surprised because I've gotten a gray one. For functionality it didn't matter, but a gray drive in a beige computer would look silly. So I also designed a 3D printable decoration plate for the tray that matched the dimensions of the original.

I could've glued to original back together, but considering that it was badly yellowed I would've needed to retrobright it, making it even more brittle. I tried a few different filaments to get the right tone of beige. In the photos you can see

// Bone White SUNLU PLA+ //

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. If I decided to not do retrobright, I would've went for

// Bone White eSUN PLA+ //

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, which perfectly matches the yellowed plastics. Knowing that those filaments look remarkably close to the real plastic will absolutely be helpful in the future.

A cd drive with a gray front standing upright next to beige-colored front panel components.

cd drive with a beige front standing upright

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Without testing the new drive I swapped front bezel and cover plate in the correct shade on and then plugged it into the Computer. And of course this drive also did not work. The way the error manifested itself was the same as with the old one. MacOS didn't complain about not having a drive, but it wouldn't talk to it either. I couldn't even eject the tray in software. When putting a disk in it by pressing the eject button on the front it would then just sit there. Like the other drive it didn't even attempt to spin up. Lovely.

I messaged the seller who sold the drive as

// tested and fully working //

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, to ask if there's a testing protocol for the drive because it doesn't work. I also tested the drive on my ThinkPad using an USB adapter, which gave me nothing. But the LG drive I used temporarily on the Mac worked just fine, so I knew the adapter wasn't at fault.

Whatever was wrong with the drive caused it to not talk to the OS.

A photo from gnome disk manager showing one SSD, one Floppy Drive and two Block devices.

A photo from gnome disk manager with the same entries as in the previous image plus a CD Drive.

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Because it was the weekend I would've needed to wait for the seller to get back to me. Which meant I had time to take the drive that came with the mac apart to maybe fix it. Maybe I could make one working drive out of two broken ones.

I want to spare you, dear reader, the details of what happened next. In short: I started partially reverse engineering the spindle driver motor in an attempt to find and fix what is causing it to not do its job. The only reference I could find about the

// Panasonic AN8294NSB //

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chip online at all, is from the

// 1997 Panasonic Semiconductor Selection Guide //

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. The guide showed a block diagram recommending Panasonic parts for a CD-ROM Drive. Multiple chips in that diagram could be found on the PCB from my drive.

// If you're in the future and find this blog post by searching for the model number of that chip: I'm sorry, your princess is in another castle. If you have a drive with the same issue and manage to fix it, let me know. //

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Just as I was starting to look for datasheets of the sibling-chips mentioned in the block diagram, I got a notification from eBay that the seller responded to my message. After some quick follow-up questions by them and some troubleshooting recommendations they offered me to send me another drive. I immediately stopped with my reverse engineering efforts after I got that message.

I've got a bunch of photos from taking apart the drive to measure stuff with my multimeter, but since that storyline is basically I dead end I'll save those for a rainy day when I'm actually trying to fix the drive.

A block diagram for a CD drive.

An unfinished pinout for a chip with 28 pins.

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After the new new drive arrived, I plugged it in, turned on the computer and put a disk in.

And it just worked?.

A beige CD drive sitting on a computer facing the back.

Finder on MacOS showing the contents of a Internet Explorer installation CD.

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