Re built PC recently, wuth MSI K9N motherboard and Athlon Dual core processor. I connected the LG DVD RW (GSA-4163B)to the board via IDE/SATA converter as board has only 1 IDE connector. However, the door wouldn't open and the led flashes about 10 times when I press the open button. Changed it to IDE then but the problem is still there. Have I fried the burner. Any ideas !!!

See if the door opens with IDE cable disconnected. If not it must be jammed. Was this DVD drive previously working or is this the first time you've tried it?

Either the mechanism has failed, or it's a jammed disc, sure. This may help - (DVD or CD drives): CD-ROM Tray not opening: Diplomacy is the art of saying 'Nice doggie!'... till you can find a rock

I tried it with the IDE cable disconnected but no joy. The drive was fine before the upgrade. It is currently recognised by the BIOS, it is visible in windows explorer, there are no problems showing up in device manager, but the leds just flash whenever i try to eject, either physically by pressing the eject button or through windows. There is no disk in the drive. When I insert the paper clip to open, I can open it...I have a bad feeling that this drive is shot. The IDE/SATA converter thing has somehow fried it.

I doubt the adapter would have affected the mechanics of the door opening. It may just be coincidence or rough handling. But in any event, if it doesn't work it needs to be replaced.