Problems occurred beginning of this week or so.
Unsure how to describe it so I uploaded a 12 seconds video on youtube.

I search for similar symptom but the closes one is this https://forum.lowyat.net/topic/3602914 but her problem is much more serious than mine.
Went to several repair shops, all gave different answer. Some said board problem, some said because screen crack while my iPad mini screen never crack.

I updated the iPad mini to the latest iOS available but problem still there.
Hope iPad sifu here can give me some advice.

have u try restoring ur ipad??

its either hardware or software problem.

if hardware, i believe its the gpu chip. which is basically the mainboard/motherboard.

if software, you need to restore the ipad.

if you have already restored it, and it still happen, then hardware lo.

Baconateer, Lowyard:
Will try to restore via iTunes.