Chosen Solution
2010 Desktop Mac Pro 5.1 was working great for years. Still using Snow Leopard 10.6.8 for making use of music software. Machine started acting odd by screen sometimes not coming on and having to restart. It worsened until one day it just would no longer come on at all. I purchased a new Radeon HD 5770 because everything on the net said the card was most likely the problem. It is not the card. After replacing it, the machine chimes it is on, but screen remains black. I use the mini port with an adapter to HDMI. Checked the cable, it is good. Tried a different cable, same thing. Monitor works fine as TV screen. What do I look for next? Everyone has phones now. All the Mac fix stores are gone. I want to stay with the desktop. My screen is 32” big. I like it like that so I can see the music I write. Also the software demands 32G of RAM. A little pocket phone can not do the job. Please Help.
You are correct, the first thing that goes on these is the video card. To test you need a KNOWN GOOD replacement card. So first find out if indeed that new card is good. The second thing that fails is the power supply. It can be a partial failure. The symptoms are usually that the machine reboots on its own. Over time this increases in frequency until it is doing it four or five times a day.
The physical slot the video card is in might be faulty. Try moving the video card into a different slot and see if that helps. If this doesn’t help maybe change which port the cable is plugged into on the monitor? Other than this I cannot tell what is wrong I am sorry.
I am facing a similar problem. My Monitor is not displaying anything , but i can hear the MAC is booting and working. After long researches, i am now going for a new card thats Metal Compatible. the new Mojave and catalina versions need metal compatible graphic cards. Why dont you also try this. According to Apple, the following graphics cards are known to be Metal-capable and compatible with macOS Mojave on the mid-2010 and mid-2012 Mac Pro models: MSI Gaming Radeon RX 560 128-bit 4GB GDDR5SAPPHIRE Radeon PULSE RX 580 8GB GDDR5SAPPHIRE Radeon HD 7950 Mac EditionNVIDIA Quadro K5000 for MacNVIDIA GeForce GTX 680 Mac Edition Apple also lists other AMD graphics cards that “might” be compatible with macOS Mojave: AMD Radeon RX 560AMD Radeon RX 570AMD Radeon RX 580AMD Radeon Pro WX 7100AMD Radeon RX Vega 56AMD Radeon RX Vega 64AMD Radeon Pro WX 9100AMD Radeon Frontier Edition You can check to see if your graphics card is compatible by holding down option while selecting Apple logo to access System Information. Under Graphics/Displays, if “Supported” is listed next to the Metal entry, the graphics card will work with macOS Mojave.
