820 4924 (2015), glitch on the screen and Freeze

[Noguinfor]

Hey,

I have 2 machines here, same model. All this machines as complete new, no one before me open that. No signals off liquid damage or components knokout!

Machine 1 - Run's perfectly, but when i run the heaven benchmarket after 1 - 2 min the screen goes black or freeze! like that:

https://drive.google.com/file/d/1tXp-6xZljGkPMS7yNwIZybGfXyee7iPe/view?usp=sharing

But this one i test in external monitor and don't show image!! DEAD!this machine after a search here in the forum I consider it to be the integrated graphics on processor!

Machine 2 - One this machine i have a doubts but I suspect the processor! take a look please:

https://drive.google.com/file/d/1dS26AylARlNqYwnDZdTU83DavzQcWieR/view?usp=sharing

Note: This one when i run the Heaven benchmarket don't goes off or freeze the program run's well!! because off this i have doubts..

what are your's opinion??

​​​​​​​thank you

 

[2informaticos]

Check if backlight voltage fluctuates too.
Also try another (compatible) LCD assembly.

 

[Noguinfor]

OK, in this morning arrives other mac pro 13 late 2013 and i test this 2 boards i spoke on top and all boards run's perfectly on it!! i run the heaven benchmarket for 5 min and no issues!!

i don't have a flat cable to test to know if it's a problem off LCD or ftlat cable!! in your's opinion what you think??

thanks

 

[2informaticos]

The blinking backlight could be from cable.
But the other problem looks like LCD issue.