hp pavilion slimline 400-224 PC

[solokay]

When I turn on the PC, it powers up, the fans turn on, but no power to monitor, keyboard or mouse. 

Normally, after turning on, fans and disc drive will either turn off or quiet down, then windows will load.
Now they stay on, as if it is getting stuck in the boot process.

[Grzwacz]

Hi,

This symptom usually indicates some type hardware problem. Have you tried tapping "ESC" at startup to get to the HP UEFI Startup Menu? Here you can enter the BIOS or run HP Diagnostics.

Possible issues could be the power supply, a component connected to the motherboard, a peripheral connected to the PC, or motherboard failure.

You have to troubleshoot components by systematically removing peripherals and components until you find the problem. This process may require using known good replacement parts.

A failing power supply may not provide enough amps to power the system; the fans will run but that is it.

It is usually cheaper to have a local PC tech take a look if you are out of warranty and don't have replacement peripherals and components to swap for testing.

Regards