MP 1,1-5,1 Nvidia - 'Black Screen' Help

[Oorha]

Hi MacRumors Community.

I'm having one of those "Black Screen" issues when trying to install a new graphics card and could really use your help. I've been searching the web, far and wide with little to no success. Trying to get the following work together:

• Apple LED Display
  
  
• Nvidia GTX 680
  
  
• MacPro 5.1
  
  
• OS X 10.11.6 (15G22010)
  

The Apple LED Display has a Mini Display Port (MDP) output and the Nvidia GTX 680 has a Displayport (DP) input. Purchased a male MDP to female DP, installed the correct Nvidia Display Drivers for my OS, used terminal to make sure it used the Nvidia Drivers (sudo nvram boot-arg="nada_drv=1), both power cables are securely attached to the card and working.

Screen Shared into my MacPro, I can see that the GTX 680 is recognised and working, Nvidia is set to the default driver however no display is being detected. Holding ALT and clicking "Detect Displays" unfortunately does nothing. The display does play audio though I suspect it's fed via the USB port.

Any and all help would be greatly appreciated!

 

[Oorha]

This is the MDP to DP connector i purchased:
https://www.takealot.com/display-port-to-mini-display-port-female/PLID54514781

 

[orph]

can you try a different cable or display?
if you have a TV try to plug it in to the TV and see what happens
is the card flashed or using it's default bios?
have you used the display before? is it known to be working? (got to ask)

the Nvidia Drivers dont matter the card has native support

99% of the time it's the cable

iv not used that display but thats some of the normal steps to check for problems

 

[Oorha]

Hi Orph, thanks for your time.

can you try a different cable or display?
Unfortunately not at this moment (home) though the card was previously installed in a colleagues MacPro and worked just fine.

is the card flashed or using it's default bios?
Not entirely sure how to find out, though again, it has worked in another Mac.

have you used the display before? is it known to be working? (got to ask)
Yes, the display works fine when the previous Radeon 5570 card is installed.

 

[h9826790]

If the card is known good. The monitor is known good. Then most likely the adaptor (cable) has problem.

 

[orph]

ok sounds like bad cable, relay 99% of the time it's the cable.

do you have boot screens?
-if no boot screen it's a PC bios
-if boot screen it's been flashed with a mac bios

any way i think it's a bad cable, there's lots of bad ones floating around

 

[Oorha]

No boot screens, boot chimes but no picture at all.

A pity if it's the cable as that's the only one available in my country.

A friend has advised me to upgrade the OS to Mojave, I'm concerned that if I do the older graphics card won't be supported and I'll essentially be left with a paperweight. Could the OS be upgraded and if the problem isn't solved, the Radeon HD5570 be reinstalled and functional?

 

[majus]

Could the OS be upgraded and if the problem isn't solved, the Radeon HD5570 be reinstalled and functional?

Not if you upgrade to Mojave; the card must support Metal. Refer to the GPU Wiki for more information:
https://forums.macrumors.com/threads/gpu-compatibility-list-for-cmp.2174600/

 

[orph]

get a new cable, not the same brand