Monitor goes black , pc still working

Hello,

So i have this problem for like a week .

I have a Radeon R7 240 which hasnt caused me problems for 3 years .
The problem is this : my monitor goes black , doesnt shut off , my power button still stays green as it should be when opened .

Notes : I've selected pause or sleep in power options to "never"
- Tried a new monitor works fine but it s and old monitor so i dont want to use it.
- Tried my monitor to another computer it doesnt go black at all
- Tried plugging it via DVI still goes black , via VGI as well

So what should i do , cause if i connect the monitor to another computer it works fine and if i connect another monitor to my computer works as well .

MY DRIVERS ARE UP TO DATE AS WELL