Monitor sometimes loses power and restarts after a few seconds

Hi,

My monitor Gigabyte G34WQC is acting weird, first I thought it was from the GPU but I've connected a different monitor to it and realised that the monitor simple turns off; PC resumes to the other monitor as they're both connected. The monitor just goes pitch black and the LED (small white presence LED) turns off. After a few seconds the monitor logo appears and everything is back to normal.

The monitor is already without waranty period so, I'm a little afraid of trying to open the monitor and try to find out if there's anything wrong with it.

I'm going to try and find some store nearby that could help, but if someone got the same issue or know what it might be, please share.

I'm guessing is something related to the powersupply as he only uses a PC supply cable (C13). I don't know, maybe a capacitor is bad, because it can stay on for like half an hour and it won't happen and then it happens every 5 mins...