Question PC only beeps if i unplug the monitor

[Undeafbear]

So, first of all, im sorry if this is the wrong place to ask for help, i searched through the forums and couldnt find anything lile the problem im having;

1 i turn on the pc, no beeps, no image but every fan is spinning

2 i unplug the hdmi cable from the graphic card (more precisely i unplug the monitor) and turn on the pc, he beeps and seems to start up normally

Things i know: the monitor is working fine by connecting my notebook to it, but that was the fartest i could get for lacking spare parts to propper test it...
I borrowed a second monitor hoping to test pc without the graphic card on the onboard vga only to find out that it only had a hdmi port...

Stores and technicians from my city will only say how much it cost for the repairs and not give me any insights of whats wrong with the pc so i can get the parts i need myself i fix it, and i also dont have spare parts to go for the minimalist route....
Kinda in the dark here :/ any help is welcome.

 

[Fix_that_Glitch]

Buy an adapter to connect the monitor.