Screen on MAC Pro keeps flashing

Swap for a different cable and for different display, and — if those swaps fail — you're headed for repair or replacement of the Mac Pro itself.

With the use of macOS 10.14 here, I'd guess this is a 2012 or earlier "cheese-grater" Mac with Metal graphics, so cleaning and re-seating memory and boards is an option for some folks, then maybe then swapping graphics, if you want to spend time and money.

great advice provided By MrHoffman above.

Mac Pro with Xeon processor has Error Correcting Code RAM memory, so don't spend more than a moment fiddling with the RAM. Absent obvious issues such as kernel panics, RAM problem on these models simply do not fester undetected.

My bet’s on a bad video/graphics card, pattyfromnorth hills… unfortunately the only way to test to see if you have a bad video card is to swap it out with a known good ( spare) one… that’s assuming you have a spare known good video/graphics card in storage/close at hand… not always the case… also you should replace the pram battery which is on the backplane , half-buried by the video/graphics card… the battery is a BR-2032, which might be hard to find, so a CR-2032 will do-it goes in plus ( +) side up, be a little gentle on the battery holder… anyways, change the battery, reseat the card( while the Mac is shut down, the side panel is off and you have touched the frame to get rid of any static electricity… you may have to push a button on the fan cage to get it to slide forward ( and to move a bar underneath the release the video card) … so that might help with re-seating it… anyways, a Mac native or Mac flashed card will work in it, if you want to spend the money that is… a 7950 or pulse RX 580 would be fine… also, see if doing an smc reset and zapping the pram a few times on startup does anything… with a bad/dead video card, probably not though..

John B

you’re welcome, pattyfromnorth hills !

hope that helped…

obviously, don’t take it to an Apple Store with Genius Bar… either, ask us or hit up Facebook for help… they have a few dedicated Mac Pro groups …

happy halllowe’en

John B

if you were running any MacOS older than 10.14 Mojave, such as on another drive, you could use "any old Mac Pro graphics card" you had on hand or could obtain for cheap.

Don't blow away your installed MacOS for this, just use a "found" other drive, internal or external.