Replace Sony DVD DRU-500A?

My DRU-500A served me well for years, but suddenly the tray does not want to stay open either empty or with a CD or DVD in it. When pressed on the button the tray closes, then kicks once and immediately opens and stays open. Any suggestions what can cause it and can it be helped?
To possibly replace it (if I really must) I am looking at the 820A. It suppose to write double layer in which I am not much interested at the moment. Will is still burn the single layer as well? I liked the Veritas software with my 500A, 820A has Nero? Is it better than Veritas was (simpler???)

As inexpensive as new burners are, it doesn’t make sense to waste much time or money trying to repair an old one. Sounds like your gears or drive motor which opens and closes the tray is going bad. If you feel brave, you can remove it from your pc, and take it apart to see what is going on.

Strange… for a day no matter what I did, the problem persisted. next day it worked well, the tray opened and closed (and stayed closed) as it suppose to. Halloween is over, some PC ghosts are still around?

Anyhow, I will keep it and replace it only when it totally stops working.