First of all let me congratulate you with your second post in almost 6 years.
Back to your problem. It's the laser lens in the HD DVD drive that is causing the trouble. If you feel up to it, you can buy a new lens at the well known auction site for 7 or 8 dollars. Look for PHR-803T or DT0811. Either one can be used.
If you don't want to open the drive, then you can buy a cheap defect A2 or A20 and swap the drives. Just be sure that the defect on that player is not drive related. A player with the Welcome bug is a sure bet. That is caused by an error on the mainboard, and the drive is normally in a perfect working order.