It's not a laser lens problem!
The fact it locked up, shut down and now wont turn on is enough to clear that it isn't a laser problem.
You may have an overheating issue - just check the rear fan is working and the vents are clear (If you can get it to power on that is).
If it doesn't power on, you've got an issue on the mainboard (i.e. Broken Fuse etc). Get them checked out.
Hope this helps...
LUFCfan