The Mac Pro First Generation is an Intel Xeon-based workstation computer manufactured by Apple Inc. The first generation model includes the machines from 2006 through 2008.

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PCI-e power connector seems broken

I'm pulling an old mac pro 2,1 out from a closet and upgrading it to use as my main editing machine. Unfortunately, it seems one of my PCI-e power connectors may be broken. So far I'v tried two different graphics cards. One has a single 6-pin power connector, the other one has two.

The card with the single connector is rather unreliable and has a lot of dead pixels. (not just in this machine)

It seemed to work fine when plugged in to one of the connectors, but using the other connector a red LED turns on on the card and when I booted the computer to a windows vista system, it booted to just a black screen with a red warning text telling me that I needed to connect power to my graphics card.

The other graphics card I tried didn't work at all. I tried a few different monitors, but none of them got a signal. I installed realVNC and it did show up as a VNC server, and I was able to connect, but it just showed windows had booted to a square black screen with just a mouse on it.

All of that suggests to me that one of the power connectors on the board of my 2,1 is broken, but it seems like an unlikely thing to fail, since the machine works fine otherwise, so it's not the PSU that has failed. After a quick google, i found no on else experiencing the same issue.

Also, I don't fully trust either of the two cards I tested with.

The single conector card is clearley at the end of it's life and could just be broken, and the other card is not support on a mac pro, and has never displayed bootscreens or worked with OS X. (although it has worked in my mac pro 1,1 before when running windows 7)

So in short, my question is: Could it be the power connector on my board? Has anyone else experienced/heard of this issue before?

I don't want to go tear my machine appart just to find out that it was the cards after all.

Answered! View the answer I have this problem too

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Are the boards Apple Mac Pro compatible? Not all graphics ares are. Can you give us the make and models of the card you want to use.


The card I ultimately want to use is an ATI Radeon 7970 (witch I plan to flash to get it working with boot screens) and the two cards I tested with are an ATI X1900 (fully mac pro compatible, but this one seems at the end of it's life) and a GeForce GTX570hd 2560MB witch is not officially compatible, but this particular card has worked with my other mac pro (a 1,1) when booting in to windows, but without showing boot screens.


Are these cards PCIe or AGP (first slot, & little tab on the bottom back corner).


@mayer The cards I tested with are both PCIe, and where both in the bottom PCIe slot in the mac pro.


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1 Answer

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It indeed seems to be the power connector. Some power cable converters and the radeon 7970 arrived, and it and the GTX570hd worked fine when connected directly to one of the PCIe power connectors, and to a molex cables from the optical bay via a converter.

When looking at the PCIe power connectors from the side, I noticed that one of them has physically been half-pulled of from the board. I suspect this is the reason it's no longer working...

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I had the same problem with the ATI 3650 HD video card. I'm presently attempting to stick a small black 4 pin molex socket I robbed off an old drive where the other broke off I lost. Will need to secure the socket with some split pin or shirt pin & maybe try a larger block if too small. How can I hold it more securely?


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