Mac Pro 5,1 (Mid 2012) - Boots up but no video output (black screen)
After a restart, my Mac Pro 5,1 boots up without video output, I can access the files and content via a networked computer, so I can confirm booting up is not an issue.
My Mac Pro:
- Mac Pro 5,1 (Mid 2012)
- 3.2GHz Quad-Core Intel Xeon
- 3 x 16GB 1066Mhz DDR3 ECC (total: 48GB)
- 1 x 1TB SATA SSD / 2 x 1TB SATA HDD / 1 x 4TB SATA HDD
- Using a 27" Apple LED Cinema Display
I was running on Mojave 10.14.6 with MSI Radeon RX 580 Gaming X 8GB before the error occurred, connect to my 27" Apple LED Cinema Display through HDMI via QGeeM HDMI to Mini DisplayPort adaptor. The system boots up with the chime with a brief red LED flash on CPU tray.
Methods I have tried:
- Reset PRAM / NVRAM (4 chimes)
- Reset SMC
- Replaced PRAM Battery (CR2032)
- Connect to Samsung Curved LED Monitor (C27F591FD) via HDMI and DisplayPort
- Connect to Apple LED Cinema Display via DisplayPort to Mini DisplayPort adaptor
- Replace GPU with MSI Radeon RX 580 Armor 8GB OC
- Tested both MSI Radeon RX 580 Gaming X 8GB and MSI Radeon RX 580 Armor 8GB OC on my PC - no issues
- Tested the Apple LED Cinema Display with my PC via DisplayPort to Mini DisplayPort adaptor - no issues
When upgrading to Mojave, I installed the new OS to my 1TB SSD and kept High Sierra 10.13.6 in its original 1TB HD. To make sure my logic board is working, I replaced the GPU with the stock ATI Radeon HD 5770 1GB and boot with High Sierra - everything works fine.
The only thing that I have not tested or replace is the power supply (I do not have the equipment to test), this is a gamble I am not willing to make if I do not know the cause of the issue, was told it was a GPU fault by a technician and bought one, yet doesn't solve the problem.
Kindly seek your advise / insights. Thank you!