My Lite-ON SSM-8515S not works!

Hi,
I’ve a Slimtype SSM-8515S, but now not works, not read a cd-rom/dvd-rom.
What I do? I change a firmware?
Now have this firmware: GRS6
Thank you!

System specs please.

Windows Xp PRO SP3
AMD Turion X2 Mobile TL-52
Acer Aspire 9300

Thank You!