[SOLVED] Switched psu and pc doesn't turn on

[Tonecas75]

Hi, I bought a new psu today but unfortunately after switching the old one (there was no problem with it but wanted to get another since it wasn't that reliable I would say) to the new one and turn the power on it would spin the fans eternally but no signal in the monitor or power to the USB devices like mouse or keyboard (I know because the leds don't glow). Can anyone help me?
Thanks in advance.

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

PSUs (old and new): make, model, wattage, age, condition?

Verify that all connections are fully and firmly in place.

Did you mix and match any or reuse any cables other than the cables that came with the new PSU?

If so, remove those cables and install/use only the cables that came with the new PSU. Do so before attempting another start.