Answer to: Asus Vivobook will not boot - black screen, no bios/uefi, nothingI had an Asus s400ca with this exact problem. It was a bad BIOS flash. Probably two bad BIOS flashes actually. I updated the BIOS from 207 to 210 and then my laptop would shut down every 30 minutes. I think that BIOS flash didn't work completely because the shut down issue seems to be a 'feature' when the CPU clock doesn't match the motherboard. Anyhow I tried downgrading the BIOS and it didn't work which resulted in it acting just like you said. All LEDs working, no fan spin. I ordered a new BIOS chip from electrikcity on ebay for $20, took the old one out, soldiered in the new one and, BAM, computer runs like new again.