Acer Aspire A380-4400

I have this computer for a yr, it just dies suddenly, won't pass the
BIOS stage, nor the drive has any activities. the screen is absolute
black. A quick check reveal power supply is OK, fan is spinning, fan
on graphic card is spinning, power reaches different parts of the
motherboard. Since I can't put it in BIOS page, nor ALT-F10 does any
good. I assume the motherboard is dead, not the disk drive. Am I
correct?

this computer is very fast (Athlon X2) but it has reliability
problems, the DVD died after 6 months, and death just after
guarantee expires.