Hi,
I had a similar problem, though my Lite-On LH-20A1S was getting more and more difficult to get the tray to open whether there was a disc in it or not. I had to push the button very hard and hold it for several seconds, releasing it, pushing it and doing this three or more times to get the tray to open. Lately, closing the tray has become difficult, needing to push and hold the button very firmly. Even a paper clip would not open the tray, nor did using computer to "eject" to open the tray. I was about to look for a new optical drive to replace mine, but found a thread at another forum that also contained the how-to given here by anonymous. The problem is, putting the tape padding or sticker on the inside of the puck (the area that makes direct contact with the spindle) only made it unable to play a disc, making a terrible whirring sound like a cat growling, though I was able to easily open and close the tray for a few times, but then it went back to struggling to open, plus the added growling sound. I figured the magnet had something to do with the problem as you can tell it is quite strong when you test it with a piece of metal, like a screw driver.
Back to square one, I took unit out of case, opened it up and removed the Duct tape padding/sticker.
Here is what I did, making up my own descriptive names for the parts in question:
Remove optical drive from machine. No need to open unit up. Remove cover plate, that can be made of plastic, or on older units, of metal. With top side up, using sharp pocket knife, carefully pry around the cover plate (and label) to loosen the glue that holds it down, working knife in angled circular direction of plate. No need to go all way round, just enough to easily remove the contents: the white plastic puck.
Turn small metal twist cover in clockwise motion to unscrew it from plastic puck, being careful not to break off any of the three plastic tabs, as I had done the first time I unscrewed one (actually, I used a screwdriver to push one of the plastic tabs upright, thinking that was how it was held down, which broke it off). If you pay attention, you can easily see from the small twist cover that you unscrew it. Once lid is removed, you will see the 10mm metal magnet that is held magnetically to the twist cover. It has a hole in the centre. You can check magnetic strength with your screwdiver or pocket knife and find out just how strong Lite-On's magnet is. This magnet is what pulls the spindle up to secure the disc in place against the plastic puck, and if the magnet is too strong, it can stretch and prematurely wear the rubber belt as it refused to release the spindle. It can also cause the spindle to not fully pull away from puck when button is pressed to open tray or close tray, resulting in the spindle dragging along the inserted disc and scratching it. At least, this is what I believe happens. I'm not an engineer.
Next, double over a piece of Duct tape to make it two layers thick (sticky sides against each other) and measure and cut a 10mm or so circle. Remove the magnet from the small metal twist plate and use magnet as a pattern. Remember to replace and center the magnet back on the twist cover. You can adjust padding/sticker with scissors to make sure it will fit in the inner circle section of puck. Then with nail, poke a hole through the middle, making it large enough to fit over the centre post of puck. (I tried making a three layer circle padding, but it was too thick and wouldn't allow the magnet and twist cover to close down, so two layers is sufficient.) Use magnet and twist cover to depress the tape flat, then with counter clockwise motion, push thumb and secure the twist cover making sure the three tabs lock in their grooves. No need for glue in this project.
Place puck back on top of unit, and close the cover plate, pushing it down to secure it. If you need glue, then do so, but I didn't as the old glue was still sufficient to hold the plate in place.
Replace unit back in machine and test it.
Mine has been working as it should for two days now, whether I am in Linux or Windows XP. The button works as well as using "eject" from computer.
One person said replacing the belt worked, which they got at an electronics supply company. It makes sense that with the strong magnet used on these units, that the belt would wear prematurely. But this fixed it for me as I have no belts on hand, but do have Duct tape. I plan to replace the belt as soon as possible, though I still think choking down the magnet was a necessity. I have an Asus optical DVD/CD RW in the same case and it is the same age and has had no problem opening and closing the tray.
I was thinking another option would be to replace the magnet with something less magnetic. We have plenty of pliable magnets on our refrigerator, and wonder if making one to fit would work without the need of any diffuser padding.
(An update to say that I fixed a second one in such manner, a 2006 unit with IDE connector and it is working fine, too. Both units also play discs and I can burn from units.)
(And a final update. Out of curiosity, I took my Asus optical drive out of an older machine and noticed it too had a cover plate under the label. I opened up the cover plate, and removed the puck, which was much easier to pull away from the spindle. The design on it was different, though it, too uses a magnet, though the magnet is on the spindle as can be seen in the final photo. Definitely less magnetic force used on it.
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