Hey everybody. I'm a PC enthusiast with very little Mac experience. A graphics designer user at my work had her Mac Pro quit working, and the IT dept. (who also have little Mac experience) tried to troubleshoot it by installing a different (PC-compatible) video card, but just bought her a new MB Pro in the end as she was due for an upgrade. I brought it home with me, and I'm curious to see if I can get it running again and put Ableton Live on it instead of using Windows for this with it's substandard audio processing. I'd like to put as little money as possible into this. Sorry about the novel I’ve written, but here goes. Specs from the label on the back: Model: A1186 EMC No.: 2180 MAC PRO/2.8_8CX/2X1G/8800GT/1TB/1TB/2XSD/RAID/WM/WK RAM was upgrade to 4 x 2 G (8 GB total) after we bought it in 2009. There are two 1 TB hard drives in RAID 1 (mirror) using the Apple Mac Pro RAID card. The former user is pretty sure that it is currently running Snow Leopard. The original 8800 GT is still in the machine. The IT dept had issues with the RAID battery in the weeks before the machine was replaced. It seems this is a pretty common problem, but not a point of complete failure. Troubleshooting done so far, with results: --When I brought it home, the machine powered on and would chime continuously, pause, then chime some more. I looked at boot chime patterns on the internet and what they would mean, but it didn’t seem to match any of the patterns, and it never seemed to chime the same way twice. --I then removed the RAID card and the hard drives and tried to boot, but still no video at all. However, at some point it only chimed once and then no more. During this time, I also removed/ replaced the RAM DIMM slots, dusted out all kinds of stuff, etc. There are no red lights on the DIMM risers after booting, so I think the RAM is fine. Since this time, it has only chimed once upon powering on - no more of the multiple chimes. --I reinserted the RAID card and the video card, and the system at this point will chime once, and the hard drives are spinning and making noise. After a minute or two, I can press the “eject” button on the Mac keyboard, and the drive will eject. If I put a disc in and close the drive, the hard drives will churn as though the OS is analyzing the disc. If I press “Caps Lock,” the light on the keyboard will activate. So, it seems to me that the system is booting into the OS, but it’s just not displaying video. --I tried booting with the OS X installation disc that came with the desktop by holding down C, and it starts churning away at the disc like a madman, but still no display. --I tried putting the 8800 GT into slot 3 (x 16 slot), and still no video output. --I tried inserting a Quadro 600 card (from a Dell PC workstation) into slots 1 and 3, but no video. It’s not a Mac card, and from what I’ve found it’s not really supported in Macs, even if you are able to interact with the OS and use hacks to get it to work. I’m pretty sure this card won’t work in any standard Mac Pro. --I tried putting in my PC’s EVGA GTX 680 SC (reference card 02G-P4-2684-KR) into slot 1 (I cannot try slot 3 due to the RAID card), but still the same thing: no video. The card was purchased in April 2012 when they were brand new. Since purchasing the card, I upgraded my PC to an ASUS Z97 PRO / i7 4770K with a UEFI firmware. Therefore, I flashed my card with the EVGA-provided UEFI firmware for the GTX 680 so that I could run Windows 8/10 in “Secure boot mode.” I've done some research, and this particular model can be flashed to the EVGA Mac firmware, which I have downloaded. However, I’m afraid to flash this Mac ROM since this is my main card for my gaming PC. Most of the threads related to flashing this card for MAC usage assume that it’s the standard non-UEFI firmware that one is beginning the process with. --I tried putting the 8800 GT into my Z97 PC in the primary PCI-Express 16 slot, and the card’s fan runs full blast and my PC will not boot at all (the display registers no signal). If I put this card into a secondary PCI-express slot, the 8800 GT does not show in Windows 10 Device Manager at all. I have no idea what should happen when you put a Mac card into a UEFI PC. (I disabled Secure Boot during this test). I have two questions: 1. I understand there are risks with flashing cards, especially if the wrong ROM is used. That being said, is it unreasonable for me to think that I can flash my GTX 680 to the Mac ROM, test to see if this works, and then flash it back to my UEFI PC ROM (which I have saved on my hard drive still)? Or is it stuck as a Mac card then? 2. I connected an Ethernet cord to the Mac, and turned it on and it seemed to be booted into OS X. However, I could not see the Mac on my network. I used my router to check this – I can see all devices connected via LAN w/ their MAC addresses. Should I have expected to see the Mac on the network, or does one have to log into OS X first before Ethernet connections are activated? TL;DR – System seems to boot into OS X, but no video can be displayed using the original Mac card or with two different PC cards. I think the logic board / hard drives are all good, and the video card needs to be replaced. Any help or ideas would be appreciated.