Monitor keeps shutting down

My cpu is on but my monitor blanks out. There is no problem with the monitor for sure. Its just that it blanks out like there's no feed going from the cpu to the monitor. I can still see the monitor, keyboard, mouse and all being on. The reboot button wouldn't work. So I switch off the ups and switch it back on. Sometimes when I switch it on, the cpu gets on but there will be no feed to the monitor so I'll keep relating it until I see the monitor lights up. This is so repetitive. I've even given it for service a few times but the problem just won't end. Is there a permanent solution to this problem?.

Thanks in advance for the help