Weird, Random screen distortion in windows safe mode and in UEFI BIOS

Hi all.
I have a loptop HP Elitebook 840 G1, with a AMD 8750M inside, and upgraded to Windows 10.

One day, I try to boot it up, it go through all the way to Windows starting logo, and go to a black screen with totally no response.
I have never seen this before and I restart it over and over again.

Around 5 times later it suddenly load into Windows and I can sign in, I click a few click and then there is black blocks distortion all across my screen.

I try to go to the safe mode of Windows 10, seems no distortion there. Then I try to run sfc /scannow and CHKDSK, they show everything fine. Then I found that the Starting menu is flashing everytime I click it , and few minutes later there is green lines distortion everywhere and hang.

Then I go to BIOS (UEFI), use system diagnostics to check and check every hardware, it said everything fine...

Then suddenly I even get green red blue line screen distortion in BIOS and auto restart...

Then it seems fine for an hour, I can go to Windows save mode again, and try disable driver. Some time later everything goes wrong suddenly. The time I am typing this, screen distortion starts immediately after the hp logo, which is BIOS UEFI, and restart over and over....

Til now I still don't know whether it is driver problems, BIOS problem, hardware problem or even virus...

Anyone have idea why is this and how to solve? I am really frustrated.