Question pc crashes when i unplug something from the extension cord

[Ctrlunderdog]

hi, my pc will crash if i remove anything from the pc that has its own power supply, for example if i remove my monitors power supply by unplugging it from either the plug or removing the hdmi cable the pc will crash, at first i thought it was a faulty graphics card, but then i unplugged my speakers from the power and the whole system crashed.
when it crashes the monitor will go black and say no signal, then after about 10 seconds the system will reboot with no errors

any suggestion?

many thanks in advance

 

[Colif]

Are you using a surge protector?

what power supply have you got?

 

[Ctrlunderdog]

at the moment no i dont have a surge protector on
its a corsair cx550m