Did a Google search on "vaio white screen" and came across this:
Question: Do you somehow SEE the VAIO startup flash screen and after that, it turns white?
Answer: Probably OS fault or corrupted OS installation.
Possible solution: after turning on the unit press F10 in succession to rebuild OS from original factory software setting
Question: After powering on the unit, you did NOT SEE the vaio logo splash screen and the screen turned white.
Answer: Hardware fault.
Possible solution: Return it back.
Question: Is it new?
Answer: IF yes, you really have to return it back for the warranty. If No, then bring it to your local repair shop.
John
March 2008