Dead computer HELP

yesterday i worked on pc no problems, turn pc off...... normal. today i push power button, all fans working: power supply, cpu, motherboard fan and fan on graphics card, but nothing happening. black screen. not even choice for opening bios. nothing. somebody know what happened to my pc ???? what part of pc is bad ? broken ?
thank you very much for any advice.

Starters for n00b hardware debugging:

(1) unplug machine, press power button, wait 1 minute, plug back in and try again.
(2) make sure the VGA/DVI cable is in snug at both ends
(3) open computer, blow dust out with "can of air", wiggle components, maybe reseat video card and memory.

Also, I see your RAID0 setup took a dump recently. Did you kick your computer?

Reset the CMOS on the motherboard (pull out the battery for 5 mins before reinserting) and try again.

Happened to me with my 1950 XTX a year ago.. video card just faulted out on me over time the fan worked and everything. Thankfully my ASUS mobo gave me the right beeps and I had my problem diagnosed in minutes.

thank you all . nothing helped . motherboard or cpu is probably dead.