MP 1,1-5,1 MacPro 5,1 stops detecting Apple 30" Cinema HD Display after disk filled up

[Riot Nrrrd]

I have a real head-scratcher here.

I have a Mid-2010 Mac Pro 5,1 cheese grater with a AMD RADEON Sapphire HD 7950 Mac Edition video card attached to an OG Apple 30" Cinema HD Display. OS is Mojave 10.14.6.

Everything worked perfectly until a couple of days ago, when a combination of creeping swap space usage along with accidentally bringing up the wrong Mail app (which caused 20+ GB of mail files to be downloaded from multiple e-mail accounts) filled up my boot SSD drive.

I couldn't even "rm" anything. My only recourse was to close all the apps/windows and after several minutes that freed up a couple of the 1 GB swap files and I had some breathing room. I was then able to delete all the newly-downloaded e-mails that Mail.app had downloaded and I got back to my normal amount of free disk space.

I then rebooted the system ... and that's when things went south. Ever since then, the system is not recognizing the Cinema HD Display and I get no video output, even though the white LCD light on the monitor is on.

Luckily I can still remote in (via Screen Sharing) from my trash can Mac Pro 6,1 and get a "Virtual Display" that lets me see everything as normal. (Thank you SwitchResX for letting me re-size that Virtual Display to 2560x1600 so it looks just like it would if the monitor was working.)

When I bring up System Information while remoted in, I have seen instances where it says it sees the FireWire and USB hubs in the Cinema HD Display as well as the Cinema HD Display itself, but I still get no video every time I try a reboot. (There have also been occasions where it does not see said FireWire/USB hubs. In fact, right now, the "USB" area in System Information is completely empty! It's not even showing the 2 front/onboard USB ports that currently have the keyboard and mouse plugged in to them.)

I thought, well, OK - filling the disk probably corrupted a .plist file someplace. I tried rebooting and resetting the PRAM (3 times/chimes) but that did not work.

This seems quite bizarre. I know the monitor is still good - it's been humming right along for over 15 years. DVI connector is solidly screwed on.

What else can I try? Hooking it up to my PC laptop (with Tripp Lite dual DVI adapter) to verify that it's still good? Resetting the Mac's SMC? What .plist files get referenced (if any) at first boot that I can trash? It doesn't even give me video if I do an Option-boot, which is worrying.

 

[weckart]

I doubt that this will help but I have had a few episodes with a Thunderbolt display, which didn't wake up after sleeping. The cure for this is to detach the cable from the Mac, then pull the power cord out and leave for a few seconds. Reattach the power cord then the TB cable. It sort of resets the monitor. Maybe your ACD needs the same?

 

[h9826790]

Disconnect both the cMP and the monitor from power source. Wait for a few minutes (5 min is more than enough), switch them back on again.

I assume your graphic card is the 7950 Mac Edition (not 9750 as per your post), then it should show you the boot screen. plist corrupted or not, won't change this fact.

If you can see the boot screen, but then the display stop working inside macOS, then it should be relatively easy to fix, just software issue.

However, if you can't even see the boot screen, then there is a chance that your ACD just die at that incident coincidentally.

 

[Riot Nrrrd]

Disconnect both the cMP and the monitor from power source. Wait for a few minutes (5 min is more than enough), switch them back on again.

I assume your graphic card is the 7950 Mac Edition (not 9750 as per your post), then it should show you the boot screen. plist corrupted or not, won't change this fact.

If you can see the boot screen, but then the display stops working inside macOS, then it should be relatively easy to fix, just a software issue.

However, if you can't even see the boot screen, then there is a chance that your ACD just died at that incident coincidentally.

Thanks. I'll try the SMC reset like you suggested. (Thanks for catching the typo, too.)

If that doesn't work I'll try hooking my HP laptop up to the Cinema HD Display via my Tripp Lite Dual DVI to Display Port adapter. I have a hard time believing the display is dead, especially with the white power light glowing ...

Thanks to both of you for your replies/sanity checks.

 

[flaubert]

If your testing ends up suggesting that the display is functional, but there is a software problem: in that case I would just do a "over the top reinstall" (of the same 14.6 Mojave version). This will refresh/rewrite all the system files and save you from trying to figuring which one of the million plist files is corrupted, while leaving your data unchanged.

How to reinstall macOS - Apple Support

You can use macOS Recovery, your computer's built-in recovery system, to reinstall the Mac operating system. Reinstalling macOS doesn't remove your personal data.

support.apple.com