Hi All, first post here, I hope somebody can help, as this is a stumper.
tl;dr Mac Pro 3,1 (early 2008) crashes: screen goes black, fans go automatically to 100%. Reasonably sure that it's a hardware problem, but can't isolate. I list all problem-solving steps I've taken in the thread below.
tl;dr questions:
Here’s the long, detailed, version:
So, I've had this workhorse Mac Pro since they first came out. Lately, it's only been for email, a few legacy Mac-only programs that I can't replace, and as a storage archive (there are 6 drives inside: 4 in the drive bays, 2 on the internal SATA ports, plus 2 external drives connected via USB). But now it’s crashing, consistently, and I can’t trust it. I'm not in a position to buy a new Mac, so I'm rather anxious to fix this one.
Symptom: screen suddenly goes black (almost as if the machine is going to sleep), 5 seconds later the fans ramp up to 100%, and I have to force a restart (sometimes two restarts, as the first, even if I wait a few minutes, won’t result in a startup chime). I do not get a kernel panic error screen.
Possible cause: I am reasonably sure that it’s a hardware problem, but that’s all I’ve been able to figure out so far. It happens randomly, as best as I can tell, e.g. if the machine is on but doing nothing, if I'm copying from one disk to another, if I'm browsing online, if I'm watching a video, etc. Can happen minutes after starting up, can happen hours after starting up.
In the past, before this crashing problem started, this Mac could be running weeks between reboots, and has always been rock solid. Well, except for one thing: for several years it has had one strange peculiarity: it doesn’t like to start up. I press the power button, fans go on, but no chime. I typically have to shut it down (holding down the power button) and then immediately start it again and then I hear the chime and it boots up normally. I have to do this at least once, sometimes twice, every time I start from cold. This has been happening years before I had this new problem of it crashing; it’s one reason I have tended to leave it on for weeks.
Another possibly relevant fact: this machine was running on 10.10.x Yosemite ever since 10.10 came out (several years ago). I only recently updated it to 10.11.x El Capitan, and it was a couple of days after that that it started this crashing problem. Note: I never updated to 10.11.x before because that version of OSX disabled my generic USB 3 PCI-E card (a well documented problem with a certain generation of USB 3 card under 10.11.x and above). Once updating to 10.11.x, I was forced to take this card out (it made a 3TB disk-to-disk copy I had to make go really really slowly, LOL), so it is not a factor in my crashing problem.
I've considered upgrading to 10.13.x High Sierra using the various hacks out there, but not until I solve this crashing problem (I'm not at all confident that 10.13.x would solve the problem).
I’ve had Macs since 1985, and have fixed quite a few in my time (software and hardware issues), but I’m stumped this time.
Steps taken to isolate the cause:
It’s possible that the graphics card is the culprit (it's a stock ATI Radeon HD 2600, been installed since purchase) but, unfortunately, I don’t have a spare to swap in to eliminate that variable.
So, it’s a possible multivariate problem (the worst kind!), but I’ve tried to remove as many variables as possible. Does anyone have any ideas as to what I could do next to solve this problem?
Many thanks in advance!
Chas
ps. this machine crashed, with a new symptom, just as I was about to post this! As normal, I forced a shutdown and then immediately restarted. I got the startup chime, then a pause, and then half a startup chime (never heard that before), then a half chime again, and then it booted. Weird!
pps. I forgot: Happy Christmas to all of you who celebrate it!
tl;dr Mac Pro 3,1 (early 2008) crashes: screen goes black, fans go automatically to 100%. Reasonably sure that it's a hardware problem, but can't isolate. I list all problem-solving steps I've taken in the thread below.
tl;dr questions:
- what sort of hardware problem leads to a black screen crash?
- what logs do I check to see what was running when the crashes happened?
- can this machine run safely with one RAM riser, instead of two?
Here’s the long, detailed, version:
So, I've had this workhorse Mac Pro since they first came out. Lately, it's only been for email, a few legacy Mac-only programs that I can't replace, and as a storage archive (there are 6 drives inside: 4 in the drive bays, 2 on the internal SATA ports, plus 2 external drives connected via USB). But now it’s crashing, consistently, and I can’t trust it. I'm not in a position to buy a new Mac, so I'm rather anxious to fix this one.
Symptom: screen suddenly goes black (almost as if the machine is going to sleep), 5 seconds later the fans ramp up to 100%, and I have to force a restart (sometimes two restarts, as the first, even if I wait a few minutes, won’t result in a startup chime). I do not get a kernel panic error screen.
Possible cause: I am reasonably sure that it’s a hardware problem, but that’s all I’ve been able to figure out so far. It happens randomly, as best as I can tell, e.g. if the machine is on but doing nothing, if I'm copying from one disk to another, if I'm browsing online, if I'm watching a video, etc. Can happen minutes after starting up, can happen hours after starting up.
In the past, before this crashing problem started, this Mac could be running weeks between reboots, and has always been rock solid. Well, except for one thing: for several years it has had one strange peculiarity: it doesn’t like to start up. I press the power button, fans go on, but no chime. I typically have to shut it down (holding down the power button) and then immediately start it again and then I hear the chime and it boots up normally. I have to do this at least once, sometimes twice, every time I start from cold. This has been happening years before I had this new problem of it crashing; it’s one reason I have tended to leave it on for weeks.
Another possibly relevant fact: this machine was running on 10.10.x Yosemite ever since 10.10 came out (several years ago). I only recently updated it to 10.11.x El Capitan, and it was a couple of days after that that it started this crashing problem. Note: I never updated to 10.11.x before because that version of OSX disabled my generic USB 3 PCI-E card (a well documented problem with a certain generation of USB 3 card under 10.11.x and above). Once updating to 10.11.x, I was forced to take this card out (it made a 3TB disk-to-disk copy I had to make go really really slowly, LOL), so it is not a factor in my crashing problem.
I've considered upgrading to 10.13.x High Sierra using the various hacks out there, but not until I solve this crashing problem (I'm not at all confident that 10.13.x would solve the problem).
I’ve had Macs since 1985, and have fixed quite a few in my time (software and hardware issues), but I’m stumped this time.
Steps taken to isolate the cause:
1) installed vanilla 10.10.1 on a separate SSD
-Crashing started a few days after I installed 10.11.x on an internal SSD (automatic upgrades have taken it to 10.11.6). So, to eliminate that variable, I installed a vanilla copy of 10.10.1 on a different internal SSD, but the crash still happens (I think that it takes longer to crash under 10.10.1 than it does under 10.11.6, but I haven't done any timing tests).
question: I’m reasonably confident I've eliminated a software cause, but which logs should I check to see what was running when the crash happened?
2) turned off computer sleep, screen sleep and drive sleep, still crashes.
3) booted from 10.10 and 10.11 recovery drive and ran disk first aid on all drives. Still crashes.
4) booted from DiskWarrior and rebuilt all directories, still crashes.
5) disconnected all drives (internal and external) except boot drive, crash still happens.
6) turned off all network services (machine is not using wifi, networking connectivity is via two ethernet connections). Still crashes.
7) checked all DIMMS. Found issues, but not related to the crashes.
-I discovered 1 dead DIMM (prob been dead for years, but it was on the top riser, and the red “I’m dead” LED was not visible), and I also discovered (today) that one of the two RAM risers is dead.
-I was able to determine there was a dead riser because machine won't start (no startup chime) if the dead riser has DIMMs. No chime when it’s the only riser installed, and no chime when it’s installed (and has DIMMs) along with the good riser. Machine will only start if the good riser, and only the good riser, is installed (well, it’ll also start with good riser and bad riser, but only if bad riser has no DIMMs. But I don’t want to keep the bad riser installed, just in case whatever is “bad” can cause any other interference or damage to the machine). Both riser slots are good; I tested the good rider in both the top and bottom slots (also tested bad riser the same way).
-Machine is now running from a single RAM riser, with 2 x 4GB and 2 x 2GB DIMMs installed. I had thought that this was the root of the problem and that I’d solved it, but it crashed (same way as usual) after a few hours in this configuration. Frustrating!
question: these Macs are supposed to run with pairs of DIMMs on both risers https://support.apple.com/en-us/HT205043 I have two pairs of DIMMs, one pair is supposed to be on one riser, the other on the other riser. Would running from a single riser cause this crash?
observation: on a hunch, I just downloaded a temperature sensor app, and the modules on the DIMMs are running at 129 degrees C. That seems really hot to me. I know that this type of RAM is supposed to run hot (the reason they all have heatsinks attached), but this hot? Interestingly, if I manually ramp up all the fans to max speed, DIMM temperature doesn’t change. I've attached a screenshot of the temperature monitor program.
It’s possible that the graphics card is the culprit (it's a stock ATI Radeon HD 2600, been installed since purchase) but, unfortunately, I don’t have a spare to swap in to eliminate that variable.
So, it’s a possible multivariate problem (the worst kind!), but I’ve tried to remove as many variables as possible. Does anyone have any ideas as to what I could do next to solve this problem?
Many thanks in advance!
Chas
ps. this machine crashed, with a new symptom, just as I was about to post this! As normal, I forced a shutdown and then immediately restarted. I got the startup chime, then a pause, and then half a startup chime (never heard that before), then a half chime again, and then it booted. Weird!
pps. I forgot: Happy Christmas to all of you who celebrate it!
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