Question Screen flickering when using full-screen ?

Jul 24, 2021
hi, so i have a lenovo ideapad l3 laptop and i have screen flickering every time i leave the laptop to on "sleep" mode overnight.

it doesnt flicker in bios/task manager, but when i go fullscreen like playing games/watch youtube, it flickers.

so, i sent my laptop for warranty claim, and they replaced the lcd screen and its cable. however, when i gave another test to let it sleep overnight, it still flickers, also only in fullscreen.

i contacted the technician and he told me to connect to an external display to see if it flickers. i connected to my tv via hdmi and it doesn't flicker on the tv but the laptop flickers.

this is the wierd part. if the tv doesn't flicker, then its the laptop screen's problem! but they just replaced a new one. so the technician said it could be the motherboard's problem, and they ordered one and its now on its way.

so my question is:
  1. what could be the cause of the flickering?
  2. after replacing the lcd screen, screen cable and the motherboard, is there any possibility that the flickering would happen again?
  3. which part other than the lcd screen, its cable and the motherboard could be the reason for the flickering?