You may want to take the drive out, and underneath the center-front of the drive you will see a slightly-curved slot with a bit of metal on the inside: Use a thin, stiff, pointy object (such as a nail) and push that metal bit towards the back of the unit: This will force the mechanism to partially eject the tape, you can then pull the tape out from there.
With the tape out and the drive powered up, see if you can push the tray back in, and push the eject button and see what happens.
I took one of my drives apart today to re-lube it as it was having a problem pulling the tape in. It's Interesting how many points that are in the drive that really Should be lubed up! (like the sides of the tape sled, and the gears underneath the sled)