MP 1,1-5,1 2012 5,1 will not boot

[Citroenfan]

Background -Upgraded with a flashed Radeon RX 580 8GB and running Mojave. Computer was working just fine. Re loaded operating system (from backup) via recovery mode to a secondary drive as I wanted to reformat the primary drive so could use opencore and put Monterey on the primary drive (1gig SS). This went just fine, re-started automatically back into Mojave on the secondary drive. Had to go out, exited Mojave. Came back a few hours later and unit will not boot nor respond to any normal commands, ie. safe mode, recovery mode, boot selector mode.

1. Was able to get it to reset PRAM. 2) Get 'start up' tone and a blank white screen. That is it. Anyone with ideas of where to go from here? As I mentioned - unit has been working fine for years with no problems.

TIA - Steve Cook

 

[tsialex]

Do you have a disk with a macOS release (10.6.4 to 10.14.6) that works? Remove all disks and install the one with macOS. Press the RTC reset button near the RTC battery.

If you can boot it, do a deep NVRAM reset and see if you are back to normal.

 

[Citroenfan]

My fault I think. What I have is a mid 2012 Mac Pro tower - not a Macbook. Have done a deep - well as deep as I could get NVRAM reset. Pulled power for 15 or so seconds, plugged back in and held keys for 3 minutes, turned back on and was able to get to 2 start up sounds over a 2 or so minute period. No change - unit turns on, get a nice 'start-up' chime and just a blank, white screen. None of the usual keyboard by-passes work, option, recovery or safe. Removing all of the on-board HD's and just leaving the bood drive changes nothing.

 

[tsialex]

My fault I think. What I have is a mid 2012 Mac Pro tower - not a Macbook. Have done a deep - well as deep as I could get NVRAM reset. Pulled power for 15 or so seconds, plugged back in and held keys for 3 minutes, turned back on and was able to get to 2 start up sounds over a 2 or so minute period. No change - unit turns on, get a nice 'start-up' chime and just a blank, white screen. None of the usual keyboard by-passes work, option, recovery or safe. Removing all of the on-board HD's and just leaving the bood drive changes nothing.

I'm not talking about a MacBook. Press the RTC reset button, near the RTC battery between the Slot 1 and 2.

This is the RTC reset button:

If reseting the RTC won't change anything, try the firmware fail safe mode. Disconnect the mains power cable, carefully remove the RTC battery so you won't break the RTC battery holder, leave the battery disconnected, wait two minutes and then connect the mains power cable. Your Mac Pro will power on automatically, see if you can boot the sure working macOS disk.

After doing that your Mac Pro started with the firmware fail-safe mode and anything that depends on the RTC or the NVRAM won't work, like BT and Wi-Fi. The best macOS release to work with firmware fail safe mode is Mavericks, btw.

 

[Citroenfan]

Sorry about that - not a real computer person - chemical engineer is a former life. Had to remove the GPU to access the re-set button. Put all back together and plugged in power. Start button instantly active. Turned off, pulled power cord and waited about 10 minutes. Plugged back in, hit start button, and pushed keys. After about 45 seconds got the start tone, screen still back. After another 35 or seconds got second start tone, then a white screen, and nothing more. Will not boot into recover, safe mode, or start select mode. Tried a back-up CPU board - no difference. Mavericks may be the best - and I can download and put on a bootable UBS stick. But how do I get the computer to even recognize much less use if I cannot access recovery or start up manger screens?

 

[tsialex]

Mac Pro firmware will always boot disks following this priority, from the greatest to the lowest:

• SATA
• PCIe
• FireWire
• USB

So, to boot a USB createinstallmedia disk automatically, you can't have any bootable disks connected to any of the other interfaces.

Fully erase a spare SATA disk, remove all other disks, connect the createinstallmedia to USB, since the SATA disk is not bootable, the MacPro firmware will scan everything else and boot the first disk it finds.

Btw, you are using your AppleOEM GPU, no? Modern GPUs will not work with Mavericks or work with firmware fail safe mode correctly.

 

[Citroenfan]

Hello again - Tried all of the above, will not boot. Get start up chime, power to keyboard comes on at chime and then goes off as screen turns on. Unit just stalls at that point. Tried a couple of times with the same results. Reminds of the defination of stupid - keep trying the same thing over and over expecting different results

 

[tsialex]

Did you tested the GPU with a PC to eliminate it?

Which GPU you tested firmware fail safe mode, since RX 580 will not work for that.

 

[Citroenfan]

The GPU was flashed to allow boot up screen. And had been working for a long time with 10.13.6 and then 1.14. The 580 will work non flashed, you just don't get the 'boot screen'. The CPU's are Apple originals. Have both a 6 core and 12 core units. Same problem with either. I just changed out the GPU with the non-metal card the unit was using. This card gets it power from the board whereas the 580 is hooked directly to the power supply. Started up and get a 'No VGA' Signal' message from the monitor. So it looks like something has really gone wrong with the computer itself. Just found a good, working, basic unit. On its way and will upgrade it with my components. Thanks for the help.