Hi there,
Taking a break from my Amiga 500 restoration I thought I'd turn my attention to my LC 575 restoration.

I previously received a 575 via mail that arrived in, shall we say, less than ideal condition. I managed to salvage a few parts from it including the logic board and I've slowly been buying replacement parts online/locally to replace the broken pieces. One such part was the main Chassis itself (I'm afraid the original did not survive shipping). I thought I had managed to source a replacement by picking up an LC 550 chassis to use in its place. I put the machine together recently and was successfully able to get it to boot to MAC OS 7.5.3. However after booting I noticed that the CD-Rom wasn't operational (note that the CD-Rom came with the LC 550 chassis) and decided I should try a different SCSI drive I had laying around.

Upon inspection though I noticed that the connection point for the CD-Rom was exactly the opposite of the replacement drive I have on hand. With one drive connecting at the top and the other connecting at the bottom. Sure enough if I slide the replacement drive into the Chassis the connectors on the cable inside are completely missed and thus no connection is made to the CD-Rom.

I'm now wondering if this is an actual difference in how the 550 Chassis was constructed (which seems odd given the rest of the Chassis seems to be the same as the 575) or if there is a way to physically move the connector on the ribbon cable inside the Chassis to mount it into a lower position so it will connect with the drive.

Thanks for any input on this.

Bumping this golden oldie, but in case anyone was searching for it, there are differences between the various models and optical drives in terms of connection. This is detailed in the July 1994 Service Guide for Macintosh computers on pages 110-111. There are three different chassis harness configurations between the 520, 550, 575, and Mac TV. Manual Inject Floppy only models and Caddy load CD drive models of the 575 and 550 use chassis config 2 with the "higher" CD connector, while the tray-loading CD models use chassis config 3 with the "lower" connector.

Mac TV and LC 520 with auto-inject drives use chassis config 1 which has the "higher" CD-ROM connector but need an adapter for the floppy connector instead of using a ribbon cable.