Cpu doesn't work

Hello, CPU fan spinning slow, no display, no power on mouse and keyboard. Sometimes it works  when i clean my ram and just tried turning off and on from main switch 3 to 4 times and sometimes it doesn't work whatever i try .I  noticed one major thing when  I turn on my pc speed of cpu fan is  slow till 30 seconds then in this case it  show no display and when fan runs slow power button of cpu doesn't work i pressed it for one minute but cpu does not shut down then i just unplugged it from main connection. Today I played some game for 3 to 4 hours then i shuts it down and after two hours when i am trying to on the issue persists. I tried ram cleaning tried multiple times by switching on/off ...

Hello,
I would like to have some help bec our cpu is not rebooting but the fan runs so fast. Was the motherboard problem?

Hello,

After booting up pc and reaching to desktop I noticed it works so slow , so I restarted it and then there was no boot and panel power switch didn't work
Now there is no display , no boot , and cpu fan spin slowly but cpu getting warmer and also power switch in panel dosen't work either


What did I do:
Switch PSU
Switch GPU
Switch ram in every positions(I mean slots)
Switch output display from vga to hdmi
taking out Battery
Reset CMOS(using jumper)

Have you any idea should I do next?
Thank you