Last night I powered off my PC after being off for approximately 16 hours I go to turn it on. I see the fans spinning the lights working inside the PC and all the parts doing as they should, however there is no output to the monitors and the keyboard and mouse are acting as if the PC is turned off when it's turned on. They light up for 3seconds and then the lights turn off as they do when the PC is powered off. I'm unsure what to do.
The best advice I could think of is checking your cables both inside and outside of your PC for any loose connections since it could happen overtime.
I had a scare like that once that my GPU had died, but it was just a loose HDMI connection.
Hope this helps!
Exactly same issue is happening with my pc. Randomly keyboard, mouse and monitor just disconnects or loose connection while CPU fan, case fans are still running. It happen anytime randomly but I notice from last two times it happen just after pc boots. The only temporary fix is to reboot the pc from cabinet reboot button.
If anyone know any fix kindly reply please.