MP 1,1-5,1 Mac Pro 4,1 Early 2009 Random Shutdown

[JayRd7]

Hi all,

I suddenly started having a problem with my Early 2009 Mac Pro Tower (4,1). After being on for several minutes, the computer will instantly turn off with no warning, as if it lost power. My first guess was overheating, so I checked for dusty fans and components, and there was some but even after cleaning it out the problem continued. My next guess was a failing power supply. I am getting the amber trickle power LED when I press the diagnostic button and no red error LEDs on the riser board, but now the computer wouldn't even turn on when I press the power button - no spinning fans, lights, anything - so I was pretty convinced it had to be the power supply. I ordered a used one off of Ebay, put it in, and the computer fired right up, but then minutes later it shut down again and I'm back to zero activity when I press the power button.

I've been able to get the computer to start again sometimes after trying random things - pulling the BIOS battery, replacing the BIOS battery with a new one, leaving the computer unplugged for a while (basically an SMC reset), pressing the SMC reset button on the logic board, but none of these tricks are consistent - sometimes they'll work and sometimes they won't, but it's becoming increasingly harder to get the machine started. Maybe I got another bum power supply but I find it odd that both PSUs would be bad and have the same behavior. I've also tried pulling RAM sticks, GPU, peripherals, but I don't even think any of this would matter as the computer doesn't even attempt to boot at all, as if it's not even plugged in - but I am getting trickle power.

I did extensive Googling on this and never found a definitive answer or solution, other than bad PSU or logic board. Wondering if anyone else has experienced this and found a fix. Thanks very much for your help!

 

[tpivette89]

Mine is doing the same thing. CPU tray and all related components test good (verified by putting it into another 4,1). Also swapped the PSU with a known good unit and no change. Sometimes powers on briefly, but quickly shuts down. Verified 5v power to logic board by hitting the test button. At this time, I suspect a bad front logic board or power button. Here is a troubleshooting guide that I have been using:

https://www.ifixit.com/Answers/View/559862/Mac+Pro+Won't+turn+on

Let me know if you do anymore testing and come up with anything, and I will do the same.

 

[MIKX]

Have you checked the ' spring rivets " on the NorthBridge chip heatsink ?

Checked for accumulated dust around the CPU tray exhaust fan ?
https://forums.macrumors.com/thread...emp-reduction-in-dual-cpu-cmp-4-1-5-1.2179729

Have you re-seated all RAM ?


is it summer where you live ?
What are your operating temperatures ( iStats Menus
https://bjango.com/mac/istatmenus/

Are you running Mac fans Control ?
https://www.crystalidea.com/macs-fan-control

 

[tpivette89]

While I don't know about the OP, I can answer with my recent experiences with the same exact issue:

QUESTION: Have you checked the ' spring rivets " on the NorthBridge chip heatsink?
ANSWER: Yes, everything looks good and there is no dust in the heatsink. In fact, I swapped the entire dual CPU tray into a known working 4,1 and it booted and ran just fine.

QUESTION: Checked for accumulated dust around the CPU tray exhaust fan ?
https://forums.macrumors.com/thread...emp-reduction-in-dual-cpu-cmp-4-1-5-1.2179729
ANSWER: Yes, I have thoroughly cleaned all dust from the entire assembly.

QUESTION: Have you re-seated all RAM?
ANSWER: Yes, again, I have tried the complete CPU tray in a working Mac Pro and it booted just fine.

QUESTION: is it summer where you live ?
What are your operating temperatures ( iStats Menus
https://bjango.com/mac/istatmenus/
ANSWER: It is summer where I live (east coast USA), but I have central air conditioning set to 68 degrees. So excessive ambient temperature is not the problem. As for a fan monitoring/control application, I usually use Macs Fan Control, but since I can't even get the machine to power on, that program is a moot point at this time.

QUESTION: Are you running Mac fans Control ?
https://www.crystalidea.com/macs-fan-control
ANSWER: see above question/answer

UPDATE: I swapped out the front I/O board with a known working unit and got no change. Also swapped out the battery with no change. I have swapped the CPU tray, power supply, battery, and front I/O board with no change. So, at this point I believe it could only be the power button or logic board.

 

[tpivette89]

Just tore everything down one more time, cleaned everything again, and reinstalled all components... dual/stock CPU tray with 2 x 2.26ghx CPUS w 12GB RAM (6 x 2GB 1066 RAM sticks), Radeon HD 4870 Apple GPU, formatted Apple/Hitachi 500GB HDD, stock Apple Superdrive (internal), no WIFI card, stock Apple bluetooth card. Even pulled an official Apple power cable from my main 4,1 Mac Pro (flashed to 5,1 and completely upgraded with newest BootROM and OS).

All components have been verified as working when removed and installed into one of my 2 working and running 4,1s. Still no power up, chime, or even a light near the power button. Just the 2 red LEDs light when plugging in the power cable, and the amber test light illuminates when the diagnostic button is pressed.

Unfortunately, it seems as though it's the logic board at this point... will swap the known good board (from one of my working Mac Pro 4,1s) to this Mac Pro tomorrow when I have time and report the results.

 

[JayRd7]

Hi all,

Sorry for the lack of response, been a busy few days. Thanks everyone for the replies and suggestions and thank you tpivette89 for your extensive testing as it seems we have identical problems, but I dont have spare machines to test against so its great that you've been able to rule some things out. I tried jumping the syspower pads tonight with no luck. Sadly it seems it may be the logic board and I'll be curious to see if you can confirm that with your test. I have to say I'm pretty disappointed that an expensive computer that's only 10 years old would have a failing board and it sounds like it's a fairly common issue with this model. Now I'm wondering if I bother replacing it or move on to something else. Just afraid a "new" (used or refurbished) board will die at some point too. Thanks again for the help, I appreciate it!

 

[tpivette89]

Hi all,

Sorry for the lack of response, been a busy few days. Thanks everyone for the replies and suggestions and thank you tpivette89 for your extensive testing as it seems we have identical problems, but I dont have spare machines to test against so its great that you've been able to rule some things out. I tried jumping the syspower pads tonight with no luck. Sadly it seems it may be the logic board and I'll be curious to see if you can confirm that with your test. I have to say I'm pretty disappointed that an expensive computer that's only 10 years old would have a failing board and it sounds like it's a fairly common issue with this model. Now I'm wondering if I bother replacing it or move on to something else. Just afraid a "new" (used or refurbished) board will die at some point too. Thanks again for the help, I appreciate it!

Unfortunately, I cannot test the swapped logic board until either Friday/Saturday. I didn't have time today to do the swap, and tomorrow I will probably only have enough time to remove the "defective" board from the non-functioning MP. The swap and test will have to wait until later this weekend.

With my machine, I have no idea what happened to it to cause the no-power condition. I bought it this way, and realistically just purchased it for the dual CPU tray (in the off-chance that it worked). Since that DID work, if the rest of the system was good, it would be a bonus. I am torn now with the decision if I should invest money in a used logic/backplane board ($70+ on ebay), or just keep the dual CPU tray and install it into my existing MP and sell off the remaining components (that work) from the defective system. This would be most profitable for me... but at the same time, I hate to see any part of these systems scrapped. Would rather sell a complete unit that someone else can use or have fun with, than part out.

Anyway, I will get back to you (JayRd7) in a day or two and post if the swapped logic board changes things. As always, since your system is different than mine and you have no real way of testing individual components like I do, your results may vary.

Good luck with your decision and your Mac Pro! Let me know if there's anything I can do to help.

 

[JayRd7]

Thanks tpivette89, I appreciate the help! I went ahead and ordered a logic board off of eBay, as I feel pretty confident at this point that that's the culprit. Should have it in next week, not sure when I'll get around to installing it but as soon as I do I will post the results! Much appreciated, -JayRd7

 

[tpivette89]

Thanks tpivette89, I appreciate the help! I went ahead and ordered a logic board off of eBay, as I feel pretty confident at this point that that's the culprit. Should have it in next week, not sure when I'll get around to installing it but as soon as I do I will post the results! Much appreciated, -JayRd7

Looks like you bought one off the same seller I have saved on my watch list! He has one left... I will be trying my logic board swap tonight to see if mine powers on... if it does, I too will be ordering that logic board.

Can't bring myself to part the other machine out, so I will be fixing it.

 

[Macschrauber]

If you guys swap the backplane boards can you check the backside for Condensator leakage. I have a theory...

 

[tpivette89]

Just swapped the logic board from one of my working Mac Pro 4,1s. All other components that I had originally swapped for testing were returned... so this unit was now 100% as I received it, just with a known working logic board.

Fired right up. Problem solved. Hope you have equal luck JayRd7.
[doublepost=1566700098][/doublepost]

If you guys swap the backplane boards can you check the backside for Condensator leakage. I have a theory...

What exactly am I looking for? I can snap a few photos of the old logic board if you want. Busy installing El Cap and going through the motions of firmware/OS updates, etc on the machine right now so it may be awhile...

 

[Macschrauber]

Check the backside for signs of leakage, greyish smear e.g. in left upper corner of the board. This is electrolyt of dead condensators.

https://forums.macrumors.com/thread...ajor-power-issue.2003237/page-2#post-27575981

 

[tsialex]

Check the backside for signs of leakage, greyish smear e.g. in left upper corner of the board. This is electrolyt of dead condensators.

https://forums.macrumors.com/thread...ajor-power-issue.2003237/page-2#post-27575981

That is flux not cleaned correctly during PCB assembly. Take any Amiga 4000 or 600 motherboards that leak electrolyte like hell, it's always on the face of the PCB, not on the back.

Gigabyte cheap PC boards have that exactly smear of flux on the back, other OEMs cut corners cleaning with the entry level boards too.

 

[Macschrauber]

Sorry to complain, Alex, but I have seen that often in my life of 30 years doing analog electronics repairing for a living. That smear is under the same caps on multiple places. And every smear is under the same cap type.

Would like to measure esd of that capacitors. Also a simple test could be to heat up the pins of that capacitors. If they make a shhhhhh sound and smell fishy its a hit.

 

[tsialex]

Sorry to complain, Alex, but I have seen that often in my life of 30 years doing analog electronics repairing for a living. That smear is under the same caps on multiple places. And every smear is under the same cap type.

Would like to measure esd of that capacitors. Also a simple test could be to heat up the pins of that capacitors. If they make a shhhhhh sound and smell fishy its a hit.

Why it's not on the face of the PCB or the solder is intact? How the electrolyte is going to the back of the board and not on the top?

If a cap is leaking the first thing to corrode is the PCB tracks around it and the solder itself, not smear the other side. A lot of Mac boards have that around manually inserted/placed components.

All my Mac Pro boards have it, it's a flux residue.

 

[Macschrauber]

Lets see if those 2 Boards what failed have this smear. My 4.1 test board is clean in that area. And another 5.1 board I have for spares is also clean. I had another 3 boards in my hand and those where clean also.

I dont want to argue, its just to investigate the cause. Caps around voltage regulators can be the cause of that failure. Nice and easy repair. A lot of 4.1 boards fail with that symptoms.

My theory is that the way of thr electrolyte is somehow thru the components legs. If those where no smd types. As written I have seen this on other boards. Look at the photo, it is mid-res, you can also see some corossion in that area. Flux wont do this.

 

[krakman]

I have a remote office in a holiday resort that i only use in the summer months. Last year when i opened the office i started up three 4.1>5.1 mac pros that has been switched off for 6 months over the winter and they all died within 5 minutes of being switched on. The symptoms are the same as described in the OP.
Occasionally the machines would boot up but then suddenly shut down and refuse to restart. All the components work fine in my other other mac pros and I also replaced a power supply which did not solve the problem.

Therefore i summmise the problem lies in the backplane, something somewhere is shorting out on the circuit board.

i have a newborn baby to look after at the moment but when i have time i will strip the boards out and send you some photos.

I replaced the broken mac pros with working units and this last winter we stored them in airtight plastic containers with silica gel. The machines survived their winter hibernation.

FYI the office is within 100 meters of the sea so I speculate high humididty may cause corrosion on the backplane??? I also had a trash can which refused to start, i took it to be repaired at an Apple store and the repair tech stated it was showing signs of water damage and asked if i had spilt anything on it!

It cost me £700 to have it repaired!

 

[JayRd7]

Hi all,

Sorry for the long delay in replying, had a busy last couple weeks and finally had the chance to swap out the logic board with a replacement. I had the same result as tpivette, the computer fired up right away after the swap and has been running fine since, so something on the board went bad. I read another forum where the poster had the same issue and they had a theory that living near the ocean had a slow rot effect on their board over time - I just happened to move right next to the ocean about 4 months ago and mine happened to die the same way too - maybe not the cause but an interesting coincidence at least. Fingers crossed that this board lasts a while.

Now I'm battling with my 2010 27" LED Cinema Display which is having the fairly common issue of randomly powering off. Everything I looked up sounded like it needed a replacement power supply board, so I swapped that but still having the same problems. Might start a new thread for that and see if anyone has a fix. Anyways, thanks for all the help and input everyone, much appreciated! Best, -JayRd7

 

[tpivette89]

Glad to hear you got it up and running, and that the logic board solved your problem!

 

[LordGrep]

This sounds exactly like the issue I have been having though mine seems now to be deady dead dead... I was having random power offs, then unable to turn on unless I unplugged it and waited like 10 hours. Now it's just not powering up at all, though I too get an orange +5v rail ok light, pressing the power button though does nothing what so ever. I have just ordered a new power supply, but by the sounds of it the consensus seems to be that it's the backplane board that is the cause. Am I reading that right? It is the backplane people are referring to when they say logic board, IE the one with the PCIE connectors on it?

Does anyone happen to know if the thing will normally power up with the processor boards removed? By power up, I just mean that I'd get just a power LED on the front to light, something that is showing me that something is happening.

I thought that the issue might have been something to do with capacitors like someone above suspected, as it was able to power on again, but only if I left it overnight unplugged, and as those caps (the big ones) are all in the PSU that is where I thought to start with the buying of replacement parts.

Any help here would be gratefully received as I am really bloody poor, I'm disabled and the government seems to think I can live on £40 for food, so it took me nearly two months to save up for a second hand PSU, so if you can help me avoid needing to save up that'd be REALLY helpful.

Thanks in advance for your time.

 

[JayRd7]

Hi LordGrep,

Sounds like the same exact thing I went through. The logic board experienced somewhat of a slow burn where it would have random power offs, then wouldn't turn on for hours, then wouldn't power on at all. I also had an orange +5v rail light even when the board had completely died. Afraid to say that it's most likely not your power supply but your logic board (or yes, backplane board, the main board in the computer). I can't exactly recall if there were any lights/indicators of life (particularly the front white LED) when I pulled the processor riser board but I don't think so. Good luck and sorry to hear about your circumstances, hopefully you can find a good cheap used logic board on eBay, I got my replacement for ~$80 with shipping and so far it has worked without an issue (here's to hoping that lasts!).

 

[zcream]

Hmm. I have now 2 mac pro 2010 gone in the past year. I live next to the beach. Also a pc and a macbook pro. The beach air is horrible for electronic stuff.