My daughter has a Dell S2418H monitor which appears to have given up the ghost. When plugged in there is no led indicating there is power at all (the PC itself works fine on another monitor). I have two identical power supplies for the monitor. When unplugged from the monitor they both illuminate the led on the power bricks and work on other devices. As soon as I plug them into the monitor they both go out and there is no power at all. It is as though there is some form of short in the monitor themselves. If I remove the power cables from the monitor the led on the powerbricks stays dimmed until I reset the supplies via the mains switch. Does anyone have any idea what could be causing this? Thanks in advance for any help.