Display not detected on DVI or HDMI. VGA works.

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olaf261 Author

Level 1

5 points

Display not detected on DVI or HDMI. VGA works.

DVI and HDMI are usable in windows, along with VGA. Holding (option) also shows the boot loader menu on HDMI, DVI and VGA. The Apple logo and boot screen progress bar appears in DVI, HDMI and VGA too.
but when the MAC OS session starts, all DVI and HDMI displays turn off.
a VGA cable must be connected to the display in order for the Mac to detect it. The Mac won’t detect a HDMI or DVI display at all
Ive tried resetting NVRAM, safe mode, internet repair.

How can the OS be restored so that the DVI/HDMI displays persist once the OSX session starts?

Mac Pro, OS X 10.10

Posted on Oct 28, 2020 4:02 PM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

140,759 points

Nov 6, 2020 5:53 PM in response to olaf261

How to reinstall macOS from macOS Recovery - Apple Support

The other way is to make your own Boot Disc, except not on a disc, on a 16GB USB stick. This BOOTAble device, once made, can be used to install again later without having to endure another download:

How to create a bootable installer for macOS - Apple Support

TIP: if you name that USB stick exactly MyVolume, you can copy and paste the command from the article directly to the Terminal command line, without error-prone editing.

Tip: the 30 minutes it takes to manufacture the USB stick provides far too little progress reporting, and will feel like an eternity.

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Answer 2

Nov 6, 2020 5:51 AM in response to olaf261

Then the problem is following the Mac Pro, however unlikely that may seem.

A re-Install of the same major version, in place (without erasing) is designed to NOT disturb your files, settings, and added Applications. It only bulk-erases system-only directories.

That said, if the drive is in trouble, replacing about 30GB of MacOS by re-writing over 350,000 files that comprise MacOS could force a troubled drive into failure. If you decide to re-Install software on your troubled Mac Pro, it is best practice to have a Trusted backup in hand before proceeding.

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Answer 3

Oct 29, 2020 10:30 AM in response to Johnb-one

Mac Pro 6,1 is ThunderBolt-2, and can supply Mini DisplayPort (subset) directly into a Mini DisplayPort cable.

If you are ruining more that ONE "legacy" {DVI, HDMI, VGA} display at a time, you may need ACTIVE adapters.

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Answer 4

Johnb-one

Level 6

9,180 points

Oct 28, 2020 5:33 PM in response to olaf261

Hi, olaf261, i’d love to help you, but i need to ask you a few questions, get some info from you, if you’d be so kind. What kind of Mac do you have? Tower—all in one(iMac) —-or laptop/notebook? If you go to the large Apple icon at the top left of your screen, and click on “About this Mac” , what does it tell you? It will also tell you the year of your Mac and what version of the Mac OS is installed on it, how much RAM, processor, and if you click on ‘more info/system report’ it’ll tell you more info , including what kind/brand of video card/graphics card/graphics processor you have and how much vram (video ram)... i guess you have tried to reset the smc/pmu as well. If you don’t know how, then you can go to apple’s support page(s) or google/yahoo that info.

good luck to you... that’s all I have for now

John B

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Answer 5

olaf261 Author

Level 1

5 points

Nov 13, 2020 3:01 AM in response to Grant Bennet-Alder

Grant said.

“A re-Install of the same major version, in place (without erasing) is designed to your files, settings, and added Applications. It only bulk-erases system-only directories.

for me that would be OSX 10.10.5 so how do I install that particular OS when my recovery partition is not working?

A new topic started with this problem:

https://discussions.apple.com/thread/252033030

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Answer 6

olaf261 Author

Level 1

5 points

Oct 28, 2020 7:19 PM in response to Johnb-one

Thanks very much.

hardware information:

Model: MacPro6,1, BootROM MP61.0116.B16, 6 processors, 6-Core Intel Xeon E5, 3.5 GHz, 32 GB, SMC 2.20f18

Graphics: AMD FirePro D700, AMD FirePro D700, PCIe, 6144 MB

Memory Module: DIMM1, 8 GB, DDR3 ECC, 1866 MHz, 0x802C, 0x31384A534631473732415A2D314739453220

Memory Module: DIMM2, 8 GB, DDR3 ECC, 1866 MHz, 0x802C, 0x31384A534631473732415A2D314739453220

Memory Module: DIMM3, 8 GB, DDR3 ECC, 1866 MHz, 0x802C, 0x31384A534631473732415A2D314739453220

Memory Module: DIMM4, 8 GB, DDR3 ECC, 1866 MHz, 0x802C, 0x31384A534631473732415A2D314739453220

AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x135), Broadcom BCM43xx 1.0 (7.15.166.24.3)

Bluetooth: Version 4.3.6f4 17916, 3 services, 27 devices, 1 incoming serial ports

Network Service: Wi-Fi, AirPort, en2

PCI Card: AMD FirePro D700, Display Controller, Slot-1

PCI Card: AMD FirePro D700, Display Controller, Slot-2

Serial ATA Device: APPLE SSD SM0512F, 500.28 GB

USB Device: Hub

USB Device: BRCM20702 Hub

USB Device: Bluetooth USB Host Controller

USB Device: Dell USB Keyboard

USB Device: Microsoft 3-Button Mouse with IntelliEye(TM)

Thunderbolt Bus: Mac Pro, Apple Inc., 19.2

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Answer 7

olaf261 Author

Level 1

5 points

Oct 29, 2020 5:18 PM in response to Grant Bennet-Alder

Hi so I’ve spent a lot of time and money on the active adaptors, having so may of them, we can say that they all do work. The display here showing the boot loader.... it’s only when the MacOS session is fully loaded that the screen turns off, because like I said System Preferences lists “unknown display”.

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Answer 8

olaf261 Author

Level 1

5 points

Nov 5, 2020 4:11 PM in response to Grant Bennet-Alder

Hi Grant,

Just a quick background on this so that we can be on the same page. When I set up the discussion here on the forum I selected MAC PRO from the menu. So to answer your question, this post is about the problem I have where DVI and HDMI display connections not detecting on the MAC PRO late 2013. I am new to the forum so I assumed that when selecting the computer from the list with the initial post, I would not have to mention those specific details in the text each time but FYI the specs of the MAC PRO are posted above too.

You suggested that somehow the display might have forgotten how to communicate with MAC OSX over EDID when connected via DVI-D or HDMI. To test this I pulled out my MACBOOK PRO Late 2013 OSX 10.9.5.

The recent photo in my last post shows that MACBOOK PRO connecting normally to the DVI-D input of the ASUS VS228 display.

You will notice that the MACPRO’s VGA connection detects the same ASUS VS228 display: here I attach that photo again where the MACPRO system report can be seen.

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Answer 9

olaf261 Author

Level 1

5 points

Nov 6, 2020 4:06 PM in response to Grant Bennet-Alder

Hi Grant,

Thanks for the suggestion of re-installing MacOS over the top of itself again without erasing. Would you be able to point me to another trustworthy post that details this course of action?

Is only use Windows on the Mac Pro anyway so I also used crystal disk mark to check the SSD health. It passed ok.

I can confirm disk utility Verification passes SMART test and yes, we have a sound back up in place. Will let you know how it goes. Thank you

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Answer 10

olaf261 Author

Level 1

5 points

Nov 5, 2020 3:07 PM in response to olaf261

FYI The displays work every time connected via HDMI or DVI-D on other MAC OSX computers!

So is re-installing MACOSX the best fix for this then?

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Answer 11

olaf261 Author

Level 1

5 points

Nov 5, 2020 3:08 PM in response to olaf261

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Answer 12

Nov 5, 2020 3:38 PM in response to olaf261

Need a little more help with that picture.

is this your alternate MacBook Pro, or is this your original MacBook Pro, and if so, what did you do to get it to work?

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Answer 13

Nov 5, 2020 5:57 PM in response to olaf261

OK, so the initial complaint was that the display could not be detected over DVI or HDMI. Are exactly the same cables/adapters in use for the MacBook Pro that DOES work?

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