Problems starting up

Hello

I have some weird problem when i start up my pc. Its hard to describe but as soon as i startup my pc the monitor doesnt turn on but my pc does my LED keyboard also turns on. After like 45 seconds my numpad LED starts to turn on and after 1:50 min of my pc starting up it automatically shuts off. But if i spam click the on/off button from my monitor combined with spamming of my keyboard and as soon as the numpad LED turns off i stop with spamming and after a few seconds the monitor turns off as nothing has happened

Help would be appreciated

Kind regards jelte