Latest Update Killed 7950 DisplayPort

[Arron Rouse]

Last night I installed the latest Apple updates (OS X 10.10.2 (14C1510)) on my 4,1. After rebooting, the DisplayPort on my Sapphire 7950 Mac Edition has stopped outputting a signal. The HDMI is still working.

My monitor is a Dell P2715Q 4k that has given problems before but this doesn't seem to be its fault for a change.

Anyone got ideas where I should start to look for a fix? I'm tempted to kill the windowserver.plist files but it would be good to know if there's already a known fix.

 

[MacVidCards]

Last night I installed the latest Apple updates (OS X 10.10.2 (14C1510)) on my 4,1. After rebooting, the DisplayPort on my Sapphire 7950 Mac Edition has stopped outputting a signal. The HDMI is still working.

My monitor is a Dell P2715Q 4k that has given problems before but this doesn't seem to be its fault for a change.

Anyone got ideas where I should start to look for a fix? I'm tempted to kill the windowserver.plist files but it would be good to know if there's already a known fix.

Try both mDP ports.

No one else has reported this yet.

 

[Donar]

I don't have that problem with my Sapphire 7950 Mac Edition card via miniDisplayPort and a Dell 2408 WFP (no 4k though).

What does your display say when connected to the mDP of the card?
No signal or signal out of sync? Do you have a second monitor to tinker around a bit with the settings for the 4k Display? (Lowering Resolution, setting refresh rates...)

 

[Arron Rouse]

Try both mDP ports.

No joy but thanks for suggestion. Have tried pretty much every cable combination now.

I don't have that problem with my Sapphire 7950 Mac Edition card via miniDisplayPort and a Dell 2408 WFP (no 4k though).

What does your display say when connected to the mDP of the card?
No signal or signal out of sync? Do you have a second monitor to tinker around a bit with the settings for the 4k Display? (Lowering Resolution, setting refresh rates...)

Glad it's just me. The monitor is reporting it as being no signal over mDP. I can tinker around by using an HDMI cable but that only gives me 30Hz so it's no good long-term.

I've now tried deleting the windowserver.plist files so that they get rebuilt. Made no difference. Guess I'll have to go hunting in boxes on the weekend for the GT120 and see if that works.

 

[Donar]

Maybe connect your MacPro to the next HDTV over HDMI as main screen, and to the 4k monitor via mDP and try to set the settings manually.

 

[Arron Rouse]

Problem solved. I spoke too soon when I said, "My monitor is a Dell P2715Q 4k that has given problems before but this doesn't seem to be its fault for a change."

I'd tried different cables, reset the NVRAM on the oMP and deleted the windowserver.plist files. Nothing. The P2715Q would only work on the HDMI.

In the end it was plugging another monitor into the mDP on the graphics card that pointed the way. That monitor worked fine. So the problem wasn't the oMP or any of the cables...

The one thing I hadn't tried was physically unplugging the Dell. Fifteen seconds without its power cable was enough. It's back to life again.

So thanks to MacVidCards and Donar for the help and P2715Q monitor owners beware!