MacPro 5,1 - cannot boot into Recover Mode.

[Steve Cook]

Has been working just fine. Started up this morning and got the error symbol (0 with line through it). Shut down and tried recovery mode. Same error. Anyone with ideas of how to solve.

 

[MacsBug]

It looks like your Hard Drive may have bit the dust. Do you have another drive with an OS to try and boot from?

 

[Steve Cook]

It looks like your Hard Drive may have bit the dust. Do you have another drive with an OS to try and boot from?

Yes, have 2 others, one with High Sierra (10.13.6) on a normal SATA drive as well as Monterey 12.7, using OCLP, on a SSD. Normal start up, was in the unit is Sonoma 14.7, using OPCL, also on a SSD. Get the exact same error with normal start up or trying to load recovery mode.

 

[MacsBug]

If the drive that has High sierra on it has gone bad then when trying to get into recovery you wont see a valid recovery partition due to the newer OS's not being supported.

Getting into recovery with OCLP is a little more tricky. You need to boot with the Option key down, and then select the OCLP Boot Loader. As soon as you select the boot loader you then hold down Command R.

 

[Steve Cook]

You misunderstand. The High Sierra drive is not used on a regular basis, just when I need to access some programs that will not load in later OS upgrades and last time I used it, a few weeks ago, it was just fine. Both of the SSD were working just fine yesterday. To have all 3 go bad, at the same time, makes no logical sense. Something has happened, at a root level, to the computer. That is what I am trying to figure out.

 

[MacsBug]

Is it possible that the OCLP Boot Loader has gotten corrupt?

 

[Steve Cook]

Is it possible that the OCLP Boot Loader has gotten corrupt?

How would that affect trying to go into the recovery mode? Ctn-R is supposed to by-pass all of that. Does not explain why the High Sierra drive will not load - OPCL had nothing to do with that one, been around for years.

 

[MacsBug]

In order to run newer OS'es on your Mac Pro you needed to install OCLP. OCLP installs its boot loader on the EFI partition of the drive that you ran OCLP on. If this was the drive that you have High Sierra on and that drive is no longer working properly then you won't be able to boot any OS.

When you hold Command R down at boot it will only boot from a valid OS for your Mac that was set as startup drive. In this case that is High Sierra. Again, if the drive was set as the boot drive, but has gone bad then you will not be able to load the recovery partition.

If the drive was still good, and you had Sonoma set as the boot drive then you would need to 1st load the OCLP boot loader before holding down Command R to since the Recovery of newer OS'es will not run natively on your Mac Pro.

So everything comes down to the drive that has High Sierra on which you installed OCLP on. If it has gone bad then you will not be able to load OCLP so none of your drives will boot.

If I was to have your setup I would have only have 1 drive at a time installed. Then setup each drive with High Sierra on it. Install OCLP and on the drive before upgrading to the OS that you want. This would give you redundancy of the boot loader being installed on each drive.

 

[Steve Cook]

The High Sierra HD does not have OPCL on it. Is my original drive. OPCL was only loaded on the SSD's. That is the reason know something has happened to the base system of the unit. More info - just set up my backup unit. The High Sierra disc loads fine.

 

[MacsBug]

In order for OCLP to work, the Boot Loader needed to be installed initially on a drive that has a system that is supported by the machine that you are using. So if you had installed the OCLP on the SSD then you would have had to have installed High Sierra on the SSD, installed OCLP and then upgraded the drive to a newer OS.

Besides the OCLP drivers being installed on the drive, the BootLoader is installed in an invisible partition called EFI and needs to be loaded on a drive that had a supported OS version for the machine when OCLP was 1st ran.

From everything that you are saying though it soounds like the main drive that has High Sierra on it has gone bad.

 

[Steve Cook]

Please re-read my above response. Switched over to my back-up 5,1 the CPU tray (12core/3.46Ghz/64GB memory), USB 3.0 card, Flashed AMD Radeon RX 580 GPU. So it is the exact same set-up as the 5,1 that developed the problem. My original High Sierra drive which does not have OPCL (why would I need) loads just fine. FYI, remove that HD, nothing else in the machine and it will load the recovery mode (cmd+R) and 'choose start up' (press 'J') as intended. The 5,1 that developed the problems would not. FWIW - doing this on my secondary unit running Sonoma 14.7.

Just trying to figure what happened to that other tower - is it something that can be rectified or is the unit, basically toast?





@3.46

 

[MacsBug]

If you take the High Sierra drive that boots in your Backup 5,1 and put it in the other machine without any other drives in it, does it boot?

Have you checked or changed the battery in the Mac Pro that was not booting? After replacing the battery make sure that you zap the PRAM.

Have you checked that the RAM is seated properly and is free of dust?

 

[Steve Cook]

The High Sierra boot disc would not start up in the'failed' 5,1 Tower. Started up fine in my back-up unit. As I mentioned the unit using now has exact same components, CPU tray, GPU and USB 3 card the 'failed' one had. I just check the little BR2023 battery that the NVRAM uses on the 'failed' unit. Measured the voltage and it was 3.133 volts. Checked a new one and got 3.302 volts. How a -0.169 volts would cause a problem, not real sure, but who knows. In any event am going to replace and change all back tomorrow. Will let you know what I find.