MP 1,1-5,1 Mac Pro 5,1 2010 - Boots up but no video output (black screen)

[MondoMania]

Hi, true Apple Geniuses,

After literally years of lurking here and finding every answer to every Mac problem I’ve had (which I greatly appreciate), I’m now officially stumped and posting for the first time. I’m really hopeful someone can put an end to my weeklong descent into madness ...

I’ll try to get straight to the issue (all relevant specs and everything I’ve tried is listed below, however).

My Mac:
2010 Mac Pro 5,1 (Westmere, 2x 2.66 GhZ Xeon E5620)
64 gigs of RAM
Running High Sierra (don’t know which; I think 10.13.6)

The Problem:
About a week ago, Mac was running OK but I was having connectivity issues (both Wi-Fi and ethernet), so I thought a reboot was in order. After that reboot, and ever since, I get absolutely no GPU output on any of my three monitors. Just a black screen. I have tried EVERYTHING in the arsenal I can find here and elsewhere, tested nearly every component, and a very frustrating week later, still nothing. I do not have a recovery disc – I know, stupid move on my part.

Here's what happens:

1. Reboot. I hear the chime.
2. No diagnostic LEDs are lighted (except for the brief flash by the DIMMs; same for the set of LEDs in the upper left corner of the logic board).
3. I am pretty sure the OS is loading, as I accidentally activated the Accessibility/Voiceover Assistant a few days ago. While it’s very difficult to navigate a blank screen blindly, the VA reads things I would normally see on the home screen, like “Dropbox is not connected … Finder …" etc.
4. FWIW, on the keyboard (full size Apple, USB), I am unable to turn on the CAPS LOCK light until well after the bootup (like 3 minutes). If memory serves it should be active shortly after I hear the chime (?)
5. Perhaps relevant: Over the past 3-4 months, the Mac would occasionally (maybe 3 times total) “reset” while I was working. It wouldn’t shut down, but would relaunch the finder and close everything I had open or just log me off. I thought that might be a logic board issue (?)

Now here’s what I have tried:

1. I have access to another Mac Pro tower at my office, so I have confirmed that all of the following work just fine on the office Mac: All three GPUs I have on hand (see below), Boot drive, and the entire processor tray. All work exactly as they should in my work Mac.
2. I replaced the logic board. Exact same result. Bootup, chime, but no video.
3. I have removed DIMMs one by one, reseated, etc. (even though they checked out fine when I put the whole tray into my work Mac ).
4. Using Carbon Copy Cloner, I cloned my boot drive. One is set to load the default MacOS graphic drivers; the other is set to load NVidia drivers. Neither has solved my problem.
5. Replaced CMOS battery
6. Reset PRAM/NVRAM
7. Reset SMC
8. Attempted every bootup keyboard shortcut I could find. PRAM reset works. None of the others do (or if they do I can’t see them working) such as Startup Manager (option key), safe mode, recovery mode, single user mode, etc.
9. Tried different electric plugs and surge protectors

What I’m using:

Video Cards: I have 3 at my disposal and was running the first two at the time of the Reboot from Hell. All three work fine in my office Mac. (I have tried them individually as well):

EVGA GeForce GTX T750i
NVidia GeForce GT120 (original stock GPU)
ATI Radeon 5770

Monitors: All working
ASUS VA32AQ (HDMI plugged into EVGA card)
Philips 272S4LPJCB (mini DP plugged into stock card)
Samsung SD850 Series S32D850T (DisplayPort plugged into EVGA card)

What’s left?
At this point, the only thing I have NOT tested or replaced is the power supply (and I have ordered one out of desperation but it’s not arriving for several days). If it is a power supply issue, this seems like an odd way to manifest itself.

I'd appreciate any insights you could share. This one has me truly stumped. Thanks!

 

[Plutonius]

I think you have to wait on the power supply.

Have you tried each GPU by itself (just one at a time) ?

 

[MondoMania]

I think you have to wait on the power supply.

Have you tried each GPU by itself (just one at a time) ?

Thanks for replying. Yes, I guess I should have been clearer that I've tried every combo imaginable with GPUs, moving SSDs and HDDs to different bays, using a single SSD and single GPU, etc. All of the above were fully functional on my office Mac.

 

[Plutonius]

Thanks for replying. Yes, I guess I should have been clearer that I've tried every combo imaginable with GPUs, moving SSDs and HDDs to different bays, using a single SSD and single GPU, etc. All of the above were fully functional on my office Mac.

So you did try one GPU at a time inside your Mac Pro ?

I think you need to wait on the power supply.

You could always get a volt meter and check out the power supply outputs when it is connected and under load ?

 

[MIKX]

MondoMania


What video cables and video adapters do you have ?
please list them here.

I think the HD 5770 is best to test with - is the 5770 EFI flashed ?
Which brand of 5770 is it ? Sapphire, Gigabyte, HIS, MSI, XFX ?

Which Mac OS are you running ? Sierra ? High Sierra, Mojave ?

Please go to your Macrumors Profile and make a SIGNATURE. All of the above info should be in your SIGNATURE plus your bootorm version

My "SIG" = signature is at the bottom of this post.

Having a "SIG" is a courtesy to members who need to know EVERYTHING about your cMP setup. It will also get you a lot more help, quicker.