The problem is that something is preventing the tray from completely opening. The design of the drive is to wait about 3 seconds for that 'something' to get out of the way. IF that doesn't happen, it times out, and closes.
I'd get back in there, make sure it's very clean. Then, try positioning the tray at different points in it's path (opening and closing). You'll find that as you adjust the tray position and then fire it up, it will either come out further, or not as far. That'll tell you which way to keep adjusting.
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Oshawa modder... up there in Canada.