CDDVD burner problem help needed

Hi all, here's hoping this is a good place to ask the experts -

All of a sudden, my HP 200i DVD-CD burner started making coasters. I get about halfway through a cd-r dvd-r when the burner stalls. I tried several different cdr and dvdr brands - none work. I tried burning with Easy, DVD Shrink, and Burnatonce - no luck. I got the firmware upgrade for the burner - it made no difference. My pc support company wants me to bring the computer in for service. Fine, but the first thing they'll do is wipe the C drive clean and install the basic software the way it was when I got it almost three years ago. That seems a bit drastic to me.

I'm no expert, but isn't it possible something physical - like a ball of dust or whatever - is clogging up the burner? Looking at the coaster discs it seems the burning process always stops at the same point, about half an inch from the outer edge.

If I open up the computer myself the warranty-free support is no longer valid, so that's not an option.

Thanks in advance for any suggestions