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4,1 can't boot

h9826790

h9826790

macrumors P6
Original poster
Apr 3, 2014
16,666
8,594
Hong Kong
My 4,1 (flahed 5,1) just dead few hours ago.

No idea what happened. It runs 24/7 as server, at the tea time period, it still good. Just before I go for dinner, l realise that the computer hanged, black screen, no respon to the caps lock key, fan spining at higher RPM but not crazy speed.

I force shut it down. And then it won't boot again.

Power button is good. White light on, fan spining at normal speed, but no start up sound and nothing display.
SMC reset, RTC reset, nil help.
Unable to perform PRAM reset due to no start up sound and no display.
Swap back the stock GPU, nil help.
No warning light related to CPU or RAM, tested with only one RAM installed, nil help.
Remove all PCIe card, nil help.
Remove all HDD SSD, nil help. Only bootable SSD, nil help. Only bootable HDD, nil help.
Reseat everything nil help.
Disconnect everything except power cable, nil help.
No CPU tray, won't power up as expected.
All diagnostics LED normal.

So, it seems the biggest suspect now is the motherboard. It won't even start the self test sequence.

Anyone has similar case before? Any more test I can do? The only test I didn't do is go back to the W3520.
 
Sounds like you've gone through all the standard troubleshooting steps already... It's a long shot but could you brows the OS drive on another mac and see if the logs have caught anything? If it was sitting there hanged for a bit then theres a chance something could be there.
 
Thanks for the suggestion, however, there is no other Mac available to read that drive at this moment.
 
h9826790 said:
My 4,1 (flahed 5,1) just dead few hours ago.

No idea what happened. It runs 24/7 as server, at the tea time period, it still good. Just before I go for dinner, l realise that the computer hanged, black screen, no respon to the caps lock key, fan spining at higher RPM but not crazy speed.

I force shut it down. And then it won't boot again.

Power button is good. White light on, fan spining at normal speed, but no start up sound and nothing display.
SMC reset, RTC reset, nil help.
Unable to perform PRAM reset due to no start up sound and no display.
Swap back the stock GPU, nil help.
No warning light related to CPU or RAM, tested with only one RAM installed, nil help.
Remove all PCIe card, nil help.
Remove all HDD SSD, nil help. Only bootable SSD, nil help. Only bootable HDD, nil help.
Reseat everything nil help.
Disconnect everything except power cable, nil help.
No CPU tray, won't power up as expected.
All diagnostics LED normal.

So, it seems the biggest suspect now is the motherboard. It won't even start the self test sequence.

Anyone has similar case before? Any more test I can do? The only test I didn't do is go back to the W3520.
Click to expand...

UPS? any storms in the area?

Try different keyboard. Sometimes you need a non-Apple kb to use to do PRAM.NVRAM reset.

SMC reset: unplugged totally and holding the power button in for 10 seconds. Wait. Reconnect. ZAP PRAM. 2-3 cycles if possible. Unplugging alone will not reset the SMC (that to me was bogus and one of the worst of Apple advice).

Slide a drive back in or try USB2 - anything but something safe.
 
The Mac die before the storm arrive (it was nice weather out there). And I am living in a high rise, the power supply here is extremely stable.

Followed your procedure to resrt SMC, nil help.

Unable to perform PRAM reset, already try connect the keyboard to different USB port, but just no power to the keyboard. It seems the Mac hang before USB avail.

Anyway, when I press the DIAG button.

PSU PWORK (green)
5V STBY (Amberra
EFI DONE (Green)
GPU OK (green)

All illuminate, so doesn't looks like the PSU problem.

And I just swap back the W3520, nil help as well.
 
Last edited:
I plug in the Apple USB mouse. The red light came on. So, the USB port is powered.

However, even though I holding the mouse button down during power up, the SuperDrive tray won't come out. May be the software drivers can't be loaded.
 
Looking at the service manual, it seems you've tried almost everything for the scenario except the following:
  • Check processor diagnostic LED (off is good, red is bad)
  • Check memory diagnostic LEDs
  • Use a single, known good DIMM
  • Reset RTC
  • Remove onboard backup battery
 
ActionableMango said:
Looking at the service manual, it seems you've tried almost everything for the scenario except the following:
  • Check processor diagnostic LED (off is good, red is bad)
  • Check memory diagnostic LEDs
  • Use a single, known good DIMM
  • Reset RTC
  • Remove onboard backup battery
Click to expand...

Thanks for the suggestions. All done, nil help, except remove the battery, should try this as I never touch it for more than 6 years now.

Update: Remove the battery, nil help either

No matter what I do, still have exactly the same symptom. Power LED on, all warning LED off, fan spinning, HDD spinning, USB port powered but not functioning, no start up tone, nothing display, won't boot.
 
Last edited:
Any progress? Might be time to at least phone Apple. I've found them quite helpful on the couple of times I've needed them, I've even had a callback from California on one issue. :)
 
No progress so far.

I doubt will they accept my case. In Hong Kong, once they know that the machine is out of warranty. They won't help me anything via the phone.

Those "Apple care" staff is actually from a 3rd party company. Not Apple staff. I think that's the problem. They will only tell me to take the box to their office, pay them to check for the problem, and then charge me another few hundred dollars to fix it.

The next step I would like to try is take the CPU tray to another Mac Pro. I have a friend has a 4,1, but he may be out of town now. Hopefully can get him to test my machine in the next few weeks. I am not sure can I just take that to the genies bar for testing purpose, if yes, that will be a even better choice for me.

At this moment. I basically narrow down to the mobo or the CPU tray. Obviously, both of them are powered, but I really don't know if they function normally.
 
It sounds reasonable to me. That's a shame about the support system over there. In the UK we call a centre in Ireland, and my experience with them has always been really good, even out of applecare.

Do you have a PC? You could, at a pinch, load up some HFS drivers and read the drive in that?
 
Not anymore, my last PC (desktop) was broken down before I own my Mac Pro.

And the only working PC now is a 15 years old IBM notebook. I can still turn it on, but obviously I need more equipment and work to make it able to access the 840Evo.
 
h9826790 said:
I plug in the Apple USB mouse. The red light came on. So, the USB port is powered.

However, even though I holding the mouse button down during power up, the SuperDrive tray won't come out. May be the software drivers can't be loaded.
Click to expand...

I would try with a generic PC mouse and keyboard. Not Apple USB device. Apple keyboard has firmware and blocked my attempts to zap pram/nvram once. Got out a trusty old MS keyboard $9 and no trouble. USB cables and extensions can be cause of problems as well.

Back on the G5's they did not scan or rescan the bus and device tree when making changes, sometimes even not seeing the SATA drive was changed - so went into OpenFirmware and reset nvram that way. No I don't like to zap pram/nvram needlessly but sometimes you have to. Same and more so with SMC resetting.
 
reddemonic said:
can you check if any has fried on the boards? i hate when this **** happen.
Click to expand...

I would like to do that, so far, can see nothing damage on the CPU tray. And didn't smell anything.

However, not yet confirm anything fired on the mobo yet. May be its time for me to study the technician guide on how to take mobo out.
 
Just took it to the Genius Bar today. They need 2 weeks to get the parts for diagnoses. Most likely is the mobo, should able to fix it within $300, a very reasonable price IMO.
 
h9826790 said:
Just took it to the Genius Bar today. They need 2 weeks to get the parts for diagnoses. Most likely is the mobo, should able to fix it within $300, a very reasonable price IMO.
Click to expand...

Hopefully it all gets fixed. So is it $300 for a processor board or $300 for a mobo? Are you running a dual or single processor board? I also read that you put the W3520 back in so that's good, but i couldnt tell if it was dual or single processors.


Out of curiosity did you happen to try unplugging the unit for 30 seconds, then hold down power button till it boots?

I actually had an issue with mine not booting once, i tried pram reset and nothing worked, but when i held down the power button after pulling the plug the unit booted and the fans turned on full blast. After it booted, i turned it off then back on and never had an issue since.

I'm not sure what holding the power button does exactly. I think i did that thinking it was a reset or something lol.
 
$300 including the mobo and labor.

At this moment, they believe that the CPU tray is good (W3520 is for single CPU system only).

If PSU also fail, will be another $170, but the chance of both fail together is low.

What you've mention is the SMC reset, I did it few times already, nil help. But anyway, thanks for your advice.
 
h9826790 said:
$300 including the mobo and labor.

At this moment, they believe that the CPU tray is good (W3520 is for single CPU system only).

If PSU also fail, will be another $170, but the chance of both fail together is low.

What you've mention is the SMC reset, I did it few times already, nil help. But anyway, thanks for your advice.
Click to expand...

Ohh smc reset that makes sense lol. Maybe you'll get lucky and find out that it wasnt your motherboard at all, but instead just a broken power supply lol. A partially broken power supply could explain why your computer didnt have any led lights go off which would also cause it to not boot.
 
do you know if is caused my our modification ? i will be worry if this happened to me.

i guess i'll keep my original mac graphic card and cpu.
 
I don't know but I don't think so.

In the technical point of view, all the upgrades are within the Mac's limit. Should not cause the mobo fail. Most likely just a coincident.
 
reddemonic said:
do you know if is caused my our modification ? i will be worry if this happened to me.

i guess i'll keep my original mac graphic card and cpu.
Click to expand...

If you stay within the power limits of the Mac Pro, there's no reason to believe a change of graphics cards can cause any harm to a computer. I don't know if there are any long term effects of using video cards with 8 pin power connector(s). But from everything I've read, the Mac Pro will typically shut itself down if power draw becomes too high before any real harm is done.

It's pretty much the same with CPUs. If you use a Xeon that has the same or lower TDP as those Apple used, I can't see how it can do any damage. Many people have even upgraded to CPUs that exceed the TDP of what Apple used and have reported zero issues.
 
Apple call me back today. They can't find out what's the problem, but they already rule out the PSU and mobo. So, most like it's the CPU tray's problem now (they never suspect the CPU tray, but I request them to get the parts and check it).

At this moment, I know it's not the CPU, GPU, PSU, RAM, HDD, Mobo. I think the only component left is the CPU tray (unless the case can cost this strange issue o_O), anything I miss? :confused:
 
h9826790 said:
Apple call me back today. They can't find out what's the problem, but they already rule out the PSU and mobo. So, most like it's the CPU tray's problem now (they never suspect the CPU tray, but I request them to get the parts and check it).

At this moment, I know it's not the CPU, GPU, PSU, RAM, HDD, Mobo. I think the only component left is the CPU tray (unless the case can cost this strange issue o_O), anything I miss? :confused:
Click to expand...

Lmfao. You have a ghost in the machine, it can't be fixed
 
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You most likely have a failed northbridge, judging by whole story.
Smart electronics workshop is able to replace it for a fraction of what Apple will charge you for new CPU tray.
Especially as you're in HK, where sourcing the right chip shouldn't be the problem.
 
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