optical disk trays won't open

I have. The tray mechanism eventually wears out. A new OD costs about $30.

Last month, I've opened my Mac Pro and took out the drives

Check to see if the slots in the front bezel are aligned with the drive (or vice versa). If not aligned with the opening it will obviously prevent the tray from coming out.

On Mac Pro 3.1, I have same problem with 1 Drive in use. I open tray by hitting aluminum enclosure on both sides of the tray with my clenched fists.

Not a final solution but it works.

I just remembered this. in the front of the Mac pro, behind the two top shutters for the optical drives, there is a screw which may be too tight.loosening it may help, also take off that little lip on the dvd tray (the piece that snaps on)

that may help

John B

I realize this is an old post but it is the closest I have found discussing the Mac Pro optical drive problem. There are other posts about iMacs and software problems, but this deals with the MP mechanical problem. I have an early 2008 Mac Pro with the original SuperDrive and a SuperDrive from my old G3. Both work fine if I get a disk in them. I went through the whole routine. Three or four tries with the eject key used to work then nothing. Drive doors not working? Something broken inside? No. THE SOLUTION - The little rubber belt on the plastic pulleys that you can see if the tray is out needs to be cleaned/rejuvenated. However you get to it, clean it with some pure alcohol or other such solvent. I used automotive belt dressing. I pulled the drives out and opened the cases. Not too hard to do. I tried a little petroleum jelly on the rails of one and some spray wax on the other. This can be done without opening the case. I'm not sure if any lubrication was really needed. THE PROBLEM - There is a metal and plastic disk built into the top case of the drive centered over the spindle. With the tray closed, the spindle and drive mechanism are up in the "play position. Without a disk inserted, the MAGNET built into the top of the spindle makes direct contact with the disk in the top case. The rubber belt looses grip over time and can't break the magnetic bond anymore. It needs to be rejuvenated (or replaced if you can find one). The drive has to drop the spindle to allow a disk to be inserted. When you try to open the drive, it senses the mechanism is stuck and it gives up. When a DVD is inserted, the spindle is up and it pulls the metal disk in the top case down on top of the DVD to hold it in place. The top metal disk spins along with the DVD. I haven't tried a band-aid fix of always leaving a disk in the drive since my drives are working fine after cleaning the belt. Having a disk always in the drive may allow enough space to weaken the bond between the magnet and the top metal disk and allow the mechanism to do its job. Hitting the enclosure with clenched fists was probably enough to break the magnetic bond but I hope the rest of the computer survived. As for replacing drives, as recommended elsewhere for this problem, I think you need to get one that is Apple compatable. Otherwise you cannot boot from it. I hope this helps at least one person. It drove me crazy for a long time pressing the eject key multiple times to get the tray to open until that finally stopped and I had to do something.

This is key. The problem is mechanical. A bit of rubbing alcohol fixed the problem for me (for now) - I was able to get the tray to come out one last time, and could reach the belt and pulley with a Q-tip.

A desperation move is to push down the aluminum door, manually open the drive with the paper clip inserted in the hole in the black faceplate of the drive itself, pull the tray open the rest of the way, and insert the disk you need.