No power- no anything

Try the steps mentioned bellow

Unplug the power cord from the All-In-One as well as the power outlet when there is still power in the All-In-One. and wait for atleast 1Min
Plug the power cord directly to a wall outlet without surg protector. (if possible connect it to a different power outlet)
Before connecting the power cord to the All-In-One press and hold the # and no 6 button and then insert the power cord, do not release the keys
until you see a message a reset (if the screen goes blank then release the keys and turn the power on)

Then check and see

Good Luck