My PC freezes and Blinks Monitor

‎I have an issue with my computer. While I'm playing LoL in the middle of the game, i noticed my screen blinks 3 times then freezes for a second. Also, my cursor keeps coming back in the middle. After that, the issue will disappear for few seconds and will back again. I also tried to restart the computer and the issue still continues from restarting until it opens. ‎ ‎Now i shut down my computer and remove the plug. After few hours, i open it and after 10 minutes probably the issue occurs again. ‎ ‎My gpu driver is updated, cleaned the RAM, and tried windows memory diagnostics tool, No problem detected.