MacPr04,1 Shutdowns & Restarts

Discussion in 'Mac Pro' started by Frank Jones, Apr 14, 2019.

  1. Frank Jones macrumors newbie

    Jun 1, 2015
    So this is a slightly older Mac, and its been running perfectly up until now. I've got several OS's on the drives, but do have one SSD with a non-approved 10.12.5(there was a helper app that bypassed Apple's security) but now, the computer runs just fine for a few minutes, then freezes, and restarts. I have multiple OS's installed over the 4 drives, and regardless of what OS I start up from, I get the same result. I've also pulled out all the drives except the SSD, which only has 10.12 and a recovery partition. I even tried to re-download the OS while in Recovery, but Apple won't allow that since the OS and CPU, to Apple, are a unsupported combo.

    I've taken out all the RAM except for 2 1Gig sticks that I'm sure came with the computer. But I have rotated all of the RAM I have and still have the same problem. I've reset the PRAM numerous times, I've even reset the CUDA (I think that's what its called... the tiny button on the motherboard), I've removed all of the PCIe cards I've added, and even replace the original video card with a different one... and I've removed the disk drives as well. I've basically stripped this computer down to the very very VERY basics, and I still have this problem. It just freezes after a short period, and then shut downs for no apparent reason. I set this up to auto login, and launch the console, and there are a whole bunch of message that mean nothing to me.. :(

    I have an Apple Start Up DVD with Hardware Test, but the disc I have didn't come with this computer, so it doesn't run.

    I've started in the Recovery mode, and used Disk Utility to check the SSD... All OK

    I've started up in Single User Mode (Command + S) but only know of one command to run. (fsck -f), but it too passes... and then freezes.

    I'm going to take it out to my garage and blow out as much dust and crap as I can to see anything helps, but I'm not holding my breath. I'm halfway thinking this is a power supply issue, but am open to trying ANYTHING to get this computer running again.

    I've had Macs in the past that have had processor issues, and have experiences numerous kernel panics... but I've not seen anything like that with this computer.... which only leaves the power supply.

    Any ideas? Suggestions to try?
  2. krakman macrumors regular

    Dec 3, 2009
    I experienced a similar problem it was due to a faulty RAM chip. the computer would work fine until it tried to address a specific part of the the RAM and then it would crash and restart

    Go to About this Mac > System report > Memory and see if the ram has Status = OK

    "I've got several OS's on the drives, but do have one SSD with a non-approved 10.12.5(there was a helper app that bypassed Apple's security)"

    are you aware you can update the firmware to make this a 5.1 mac pro thereby allowing you to install Mojave without requiring any hacks? all info is here:

    Screenshot 2019-04-15 11.31.43.jpg
  3. Frank Jones thread starter macrumors newbie

    Jun 1, 2015
    krakman. Thanks for your advice. In System Preference, all the RAM says OK. (would it even start up if there was a RAM problem..??). I've got 22Gigs, 6 of which came with the computer, and are all labeled the same. RAM was one of my first thoughts, so I'd taken it all out, and just rotated in 2 of the original 6 sticks, in hopes of finding one (or 2) that was causing the problem. But you have pushed me in the direction of this being a RAM problem. I did download memtest, and am running it while in Maverics, which seems to have a lesser RAM footprint that some of the more recent OS's. And as I'm wiring this, of course, the computer just froze, so now I'm going to go back to square 1 with RAM, take it all out except for some of the original sticks, and run the memtest more to try and isolate the problem. I use this computer mainly for accounting, and starts up in the morning and shut downs at night on schedule, and has been great up 'til this last week. While I suspose this is a RAM problem, I'm not thinking of ways and things that my have damaged them all in some fashion, while the machine was running... or even NOT running.. a very close lightning strike perhaps... this computer is at my office and I'm not there 24/7 so it could have easily been something like that. It IS plugging into a battery UPS, but the RAM is damaged, I don't doubt it may have come in thru the AC as well. Anyway.. thanks for your tips. I'm hoping this is really a RAM problem, and not a power supply one.
  4. tsialex macrumors 68040


    Jun 13, 2016
    Yes, you can start a Mac Pro with problematic RAM. ECC error correction make more troublesome to find some types of RAM errors, most that happens after some temperature only are difficult to track.

    Power supply problems usually start to show when you can't wake up your Mac Pro from sleep anymore.

    Did you run AHT? You can download and install to a USB stick with this instructions:
  5. Frank Jones thread starter macrumors newbie

    Jun 1, 2015
    I actually have the hardware test on a CD but coudln't get it to boot (it may be the wrong version for the computer that I have) ... so I may try your USB stick instructions... and the RAM seems so cheap these days, I also considering just getting 2 new sticks to see if RAM is really the problem. The building this computer is in is OLD, and we've had a TON of electronics go out that really shouldn't have... so I also suspect that may be part of the problem... Thanks again...

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