If there is absolutely no sign of life then try toggling the power switch off and back on again. Check the power cable is securely plugged in at each end and the power socket switch is turned on. Try swapping the power cable for one you know works, and plug it into a wall socket you have tested with another device.
Try a swap test with a computer and/or monitor that you know works and see if the problem can be reproduced; or if its a laptop screen then try connecting an external monitor and see if that works. Don’t forget to check it’s attached to a pc that is switched on!