Apple CD 300 External Ejects Caddy on Insert

madcow

New Tinkerer
Aug 9, 2022
9
1
3
Dug out an old CD caddy external scsi drive. Connected it to my LC 550 (no internal cd drive) and powered everything up. Seemed ok at first, loaded up an old mac demo cd in a caddy and inserted it. Caddy pulls in fine but basically immediately ejects. I don't have another caddy drive around to test it with, but the door on the caddy slides just fine. Anyone run into this before? It seems to never spin the disc. I used to have a different 3rd party caddy drive on this machine in the 90's so I am hoping to get this working to complete the experience.
 

madcow

New Tinkerer
Aug 9, 2022
9
1
3
Thank you for the info - it didn't occur to me that the drive would have SO MANY CAPS.

I'll crack it open and see what I can do. I should have some replacements laying around.
 

Garrett

Tinkerer
Oct 31, 2021
103
108
43
MN, USA
Yup, horrible isn't it! I've done two or three of these. To make it easier, I removed the larger ROM chip and used smaller footprint caps in that area to make soldering them a little easier. The angles are a bit tricky but it's do-able.
 

madcow

New Tinkerer
Aug 9, 2022
9
1
3
Just to confirm for posterity - wow those caps were bad on the AppleCD 300 drive itself. I haven't replaced them yet, moving slow to try avoiding pad damage, but it seems fixable. Haven't seen/smelled such a leaky mess in a while and I have been cracking open a lot of macs recently.
 

madcow

New Tinkerer
Aug 9, 2022
9
1
3
Well I got some new caps on the board mostly without issue regarding the pads, but am still getting the same problem. I checked that I got the socket chip reseated correctly. Going to reflow the capacitors again just to see. What do you mean by cleaning the eye? I assume a little lens? Right now it doesn't seem to try reading the disc before spitting the caddy out.
 

retr01

Senior Tinkerer
Jun 6, 2022
2,473
1
793
113
Utah, USA
retr01.com
What do you mean by cleaning the eye? I assume a little lens?

Correct. Sometimes when it is not clean, it is not reading properly and just ejects the caddy.

Right now it doesn't seem to try reading the disc before spitting the caddy out.

And it also can be other issues like somewhere on the controller board which you are working on. I really would love to find a write up about those issues because all Apple ever does back in the day is replace the whole unit. Not many folks see the problem and do a very cheap fix, you know?
 

madcow

New Tinkerer
Aug 9, 2022
9
1
3
Well good news - ish - I gave the lens a little clean and jiggle and then it took a CD and kept it in. Excited, I tried a few more and found that SOMETIMES it accepts the CDs, I have even installed a game off one, but most of the time it will eject right away. This makes me think the recap worked alright (the caps were so leaky it obviously needed a swap), but something else is off.

I haven't touched the caps on the front panel yet - could that be the problem?