MP 1,1-5,1 MacPro 5.1 power issue

[Jero123]

Hi,

I have a problem with my Mac Pro 5.1 and I though maybe one of you could help me resolve the issue. I'll try to give as much detail as I can on what is going on.

First, I the problem occurred when the tip of a lightning connector (connected on one of the front USB ports) accidentally touched one of the Firewire port (also on the front panel). When this happened, my USB devices were shut down.

I have the unplugged the computer and waited about 1 minute. When I plugged back the computer, it tried to power on without success, and kept trying over and over again (see video)

The red DSI510 Led keeps flashing because the computer continuously restarting its power cycle.

Here's what I tried to fix this issue :
- Replace the PSU -- nothing changes
- Disconnect the front USB extension panel -- computer still powers on and I can't
- Clean fans, heatsink and case interior for dust
- I tried disconnecting all devices (hdds, GPUs, PCIe cards, etc) - When I try this, the computer gets through its power cycle and seems to start propertly. However when I press the power button to shut it down, it won't turn on again. I had to disconnect the power cable, remove the CR2032 battery and replace it. When I do so, the computer restarts. Then, when I add any component, I get the repeating power cycle issue.

Is there something I am missing ?

Any help would be greatly appreciated

Thanks,

 

[w1z]

- I tried disconnecting all devices (hdds, GPUs, PCIe cards, etc) - When I try this, the computer gets through its power cycle and seems to start propertly. However when I press the power button to shut it down, it won't turn on again. I had to disconnect the power cable, remove the CR2032 battery and replace it. When I do so, the computer restarts. Then, when I add any component, I get the repeating power cycle issue.

Seeing that the you are able to boot properly without any peripherals but you are still having problem with turning it on again points to a problem with your CPU, Memory, Airport/Bluetooth modules and/or Logic Board. You certainly shorted something but in order to find out the extent of the damage you need to test each and every component/peripheral with your logic board. You already replaced the PSU so no issues there.

Try this - disconnect power cord then remove ALL peripherals including Airport and bluetooth modules, CPU and memory then reconnect power cord and push the diagnostic button - what do you get/see? Also, what happens when you attempt to power on?

 

[tommy chen]

i think you kill your backplane (southbridge?)

 

[tsialex]

MP5,1 backplane has resettable fuses, polyfuses, remove your Mac Pro from power, disconnect it totally and wait 24h.

Sometimes it's just the fuses and it will work again after 24h.

 

[Jero123]

Ok, I'll try to remove the airport / bluetooth modules and CPU tray when i finish work today and will get back to you.

Concerning the fuses, I did let it rest unplugged for more than a week. Do I need to remove the CR2032 battery for them to reset ?

 

[tsialex]

Concerning the fuses, I did let it rest unplugged for more than a week. Do I need to remove the CR2032 battery for them to reset ?

No, it just powers the clock, but you can remove it, if you want to.

You need to remove all USB/FW connections, display and PSU power cable.

 

[Jero123]

OK so it doesn't seem to be the fuses since the computer was left unplugged with no devices connect for more than a week.

I tried disconnecting everything from the logic board. If I press the DIAG led button after doing so, I get the 5V STBY led. I then added the processor tray, with RAM modules removed. When I tried to power up the unit, it did 2 power cycle (as shown in the video, but only repeated twice) and started. If I press the diag light, those led are lit :
- PSU PWRON
- 5V STBY
- SYS PG
Fans are running normally. Then if I press and hold the power button, the device stops, as expected. When I press the led button, the 5V STBY is lit. After that, I can't restart the unit by pressing the power button unless I remove the CR2032 battery for 10 seconds.

I did some more testing adding components to the mix. I discovered that when adding a USB expansion PCI card (which I guess is a low energy component), it eventually starts after 10 - 15 power cycles. I took a video of this :

Any way I can make sure the problem is the logic board ?

 

[tsialex]

OK so it doesn't seem to be the fuses since the computer was left unplugged with no devices connect for more than a week.

I tried disconnecting everything from the logic board. If I press the DIAG led button after doing so, I get the 5V STBY led. I then added the processor tray, with RAM modules removed. When I tried to power up the unit, it did 2 power cycle (as shown in the video, but only repeated twice) and started. If I press the diag light, those led are lit :
- PSU PWRON
- 5V STBY
- SYS PG
Fans are running normally. Then if I press and hold the power button, the device stops, as expected. When I press the led button, the 5V STBY is lit. After that, I can't restart the unit by pressing the power button unless I remove the CR2032 battery for 10 seconds.

I did some more testing adding components to the mix. I discovered that when adding a USB expansion PCI card (which I guess is a low energy component), it eventually starts after 10 - 15 power cycles. I took a video of this :

Any way I can make sure the problem is the logic board ?

You said the Lightning cable was connected on front USB ports. Did you disconnected the front board from the backplane (disconnect the sheathed cable) and powered the backplane via the power-on pads?

If the short circuit is on the board the manage the frontal ports, maybe you just need to replace it. Check this before buying a new backplane.

 

[Jero123]

Yeah I did try to disconnect the front panel. When i plugged the computer, it went trough its power cycle loop by itself, i did not have to short the pads.

Also, when the short happened, all my usb devices were shutdown (eventhose connected on tje back panel)

 

[tsialex]

Yeah I did try to disconnect the front panel. When i plugged the computer, it went trough its power cycle loop by itself, i did not have to short the pads.

Also, when the short happened, all my usb devices were shutdown (eventhose connected on tje back panel)

Next step is to replace the backplane, with some searching and without hurry you can get one from eBay around $70.

Btw, what is that clicking noise? It's the PSU relay?

 

[Jero123]

Ok,
I’ll get back to you when I manage to replace it.

About the clicking noise, it does come from the PSU.

 

[tsialex]

Ok,
I’ll get back to you when I manage to replace it.

About the clicking noise, it does come from the PSU.

Do you have access to another MP4,1 or MP5,1 to test the PSU?

It's a real MP5,1? If it's a flashed one, you have to buy a MP4,1 backplane.

 

[Jero123]

This is what I have

does this help?

i don’t have access to 2 computers, but both of my PSU behave the same way

 

[tsialex]

This is what I have

does this help?

i don’t have access to 2 computers, but both of my PSU behave the same way

Yep, a real MP5,1.

From my spreadsheet:

• 1LTB are 2009 backplanes made in 2009 for MP4,1, very early ones.
• 1LTC are 2009 backplanes made in 2009 for MP4,1.
• BH7A are 2009 backplanes made in 2010 for MP4,1.
• BH9A are 2010/2012 backplanes made after mid-2010 for MP5,1 and before 17-digit serial change.

 

[tommy chen]

This is what I have

does this help?

i don’t have access to 2 computers, but both of my PSU behave the same way

yes, it is a real 5,1

 

[Jero123]

Well, I have received a replacement logic board and installed it today.

It's alive!

Thanks for your help guys, really glad I could repair it.

 

[Kelinu]

Hey guys how can you tell if it's an actual 5.1 or flashed? I am having powering issues with my MP5.1 - not powering on whatsoever, completely dead. Tried different PSU, but still nothing. When I plug to mains (the first two LEDs on the backpanel blink in red momentarily) and I press the DIAG button the 5V LED lights up in amber. That's it. Any help please?? I tried without any peripherals (i.e. no SSD, Graphics card and RAM) to no avail. Thanks in advance

 

[tsialex]

Hey guys how can you tell if it's an actual 5.1 or flashed? I am having powering issues with my MP5.1 - not powering on whatsoever, completely dead. Tried different PSU, but still nothing. When I plug to mains (the first two LEDs on the backpanel blink in red momentarily) and I press the DIAG button the 5V LED lights up in amber. That's it. Any help please?? I tried without any peripherals (i.e. no SSD, Graphics card and RAM) to no avail. Thanks in advance

Serial number of the backplane, MLB:

See my writeup for another user:

Backplanes:

From my spreadsheet, the MLB suffixes below show the model year of the backplane:

• 1LTB are 2009 backplanes made in 2009 for MP4,1, very early ones.
• 1LTC are 2009 backplanes made in 2009 for MP4,1.
• BH7A are 2009 backplanes made in 2010 for MP4,1.
• BH9A are 2010/2012 backplanes made after mid-2010 for MP5,1 and before 17-digit serial change.

SMC:

The best way to know if your Mac Pro is a real mid-2010/mid-2012 is checking the SMC version with >AboutThisMac>SystemReport>HardwareOverview>SMCVersion(system).

• If the System SMC version is 1.39f5, it's an early-2009 Mac Pro.
• If the System SMC version is 1.39f11, it's a real mid-2010 or mid-2012 Mac Pro.

Mac Pro early-2009 and mid-2010/mid-2012 SMC versions can't be changed by users or technicians, only by the big Apple Repair Centers that refurbish Apple backplanes and CPU trays can upgrade or downgrade it during the refurbishment process.​

Always use the SMC version to identify a Mac Pro early-2009 from a mid-2010/mid-2012. SMC of an early-2009 Mac Pro is not upgradeable at all*. Apple never released SMC upgrades for any Mac Pros newer than MP2,1, so, no SMC firmware available or the security key necessary to do the upgrade is available outside Apple labs.

*The only way to upgrade a Mac Pro early-2009 SMC is desoldering it from a mid-2010 or mid-2012 backplane and soldering to it to the early-2009. Since it's a 144-pin TQFP micro-controller, it's a very difficult operation without the necessary training, correct equipment and supplies.​

CPU trays:

While the CPU trays don't have BootROM firmware, only the backplane has it, the CPU tray has SMC firmware and CPU trays from early-2009 and mid-2010/mid-2012 have different SMC versions too, exactly like the backplanes from early-2009 and mid-2010/mid-2012.

For the SMC work correctly, both the tray and the backplane SMC are required to match. If the SMC versions differ, the SMC enters fail-safe mode and all fans of your Mac Pro will run at maximum RPM, full time. So, you can't use an early 2009 backplane with a mid-2010/mid-2012 CPU tray, or vice-versa.

820-2482-A is the Apple copyright register number for the mid-2010/mid-2012 CPU tray design. Apple used mid-2010/mid-2012 single CPU trays to repair early-2009 Mac Pros, they have the tools to change the SMC version that no one else have access and these tools never leaked, so the design register number and the CPU Tray Part Number can provide a false identification with some cases. © date is always 2009, even for mid-2010/mid-2012.

Since your currently CPU is a quad core, you have a Single CPU Mac Pro. Without replacing the CPU tray for a Dual CPU Tray, you can only upgrade to a hex core CPU like W3680/W3690 or X5680/X5690.

The mid-2010/mid-2012 Dual CPU Tray Part Number is 661-5708. This Part Number can be seen on the label that has a barcode.

Type of Tray:	2009 Part Number:	2010/2012 Part Number:
Single processor board	661-4999	661-5707
Dual processor board	661-4998	661-5708

Types of Xeon supported by each tray model:

Btw, W3xxx processors can only be used with Single CPU trays, they are single QPI link or single CPU processors.

Dual CPU trays can only use dual QPI Xeons (X5xxx or the low power versions L5xxx and E5xxx).

Single CPU trays can work with dual or single QPI Xeons (W3xxx, X5xxx or the low power versions L5xxx and E5xxx), don't matter.

For more info about supported Xeons, see the table on the first post of the thread below:

Mac Pro CPU Compatibility List

Bokkow and I have created a Mac Pro CPU compatibility list. The intent is to cover all relevant and compatible CPU upgrades for all Mac Pros. These are asked about over and over and over again, so I thought it would be nice to have it all in one place. Constructive criticism, corrections to...

forums.macrumors.com

 

[Kelinu]

Serial number of the backplane, MLB:

View attachment 916718

See my writeup for another user:

Backplanes:

From my spreadsheet, the MLB suffixes below show the model year of the backplane:

• 1LTB are 2009 backplanes made in 2009 for MP4,1, very early ones.
• 1LTC are 2009 backplanes made in 2009 for MP4,1.
• BH7A are 2009 backplanes made in 2010 for MP4,1.
• BH9A are 2010/2012 backplanes made after mid-2010 for MP5,1 and before 17-digit serial change.

SMC:

The best way to know if your Mac Pro is a real mid-2010/mid-2012 is checking the SMC version with >AboutThisMac>SystemReport>HardwareOverview>SMCVersion(system).

• If the System SMC version is 1.39f5, it's an early-2009 Mac Pro.
• If the System SMC version is 1.39f11, it's a real mid-2010 or mid-2012 Mac Pro.

Mac Pro early-2009 and mid-2010/mid-2012 SMC versions can't be changed by users or technicians, only by the big Apple Repair Centers that refurbish Apple backplanes and CPU trays can upgrade or downgrade it during the refurbishment process.​

Always use the SMC version to identify a Mac Pro early-2009 from a mid-2010/mid-2012. SMC of an early-2009 Mac Pro is not upgradeable at all*. Apple never released SMC upgrades for any Mac Pros newer than MP2,1, so, no SMC firmware available or the security key necessary to do the upgrade is available outside Apple labs.

*The only way to upgrade a Mac Pro early-2009 SMC is desoldering it from a mid-2010 or mid-2012 backplane and soldering to it to the early-2009. Since it's a 144-pin TQFP micro-controller, it's a very difficult operation without the necessary training, correct equipment and supplies.​

CPU trays:

While the CPU trays don't have BootROM firmware, only the backplane has it, the CPU tray has SMC firmware and CPU trays from early-2009 and mid-2010/mid-2012 have different SMC versions too, exactly like the backplanes from early-2009 and mid-2010/mid-2012.

For the SMC work correctly, both the tray and the backplane SMC are required to match. If the SMC versions differ, the SMC enters fail-safe mode and all fans of your Mac Pro will run at maximum RPM, full time. So, you can't use a early 2009 backplane with a mid-2010/mid-2012 CPU tray, or vice-versa.

820-2482-A is the Apple copyright register number for the mid-2010/mid-2012 CPU tray design. Apple used mid-2010/mid-2012 single CPU trays to repair early-2009 Mac Pros, they have the tools to change the SMC version that no one has and these tools never leaked, so the design register number and the CPU Tray Part Number can provide a false identification with some cases. © date is always 2009, even for mid-2010/mid-2012.

Since your currently CPU is a quad core, you have a Single CPU Mac Pro. Without replacing the CPU tray for a Dual CPU Tray, you can only upgrade to a hex core CPU like W3680/W3690 or X5680/X5690.

The mid-2010/mid-2012 Dual CPU Tray Part Number is 661-5708. This Part Number can be seen on the label that has a barcode.

Type of Tray:	2009 Part Number:	2010/2012 Part Number:
Single processor board	661-4999	661-5707
Dual processor board	661-4998	661-5708

Types of Xeon supported by each tray model:

Btw, W3xxx processors can only be used with Single CPU trays, they are single QPI link or single CPU processors.

Dual CPU trays can only use dual QPI Xeons (X5xxx or the low power versions L5xxx and E5xxx).

Single CPU trays can work with dual or single QPI Xeons (W3xxx, X5xxx or the low power versions L5xxx and E5xxx), don't matter.

For more info about supported Xeons, see the table on the first post of the thread below:

Mac Pro CPU Compatibility List

Bokkow and I have created a Mac Pro CPU compatibility list. The intent is to cover all relevant and compatible CPU upgrades for all Mac Pros. These are asked about over and over and over again, so I thought it would be nice to have it all in one place. Constructive criticism, corrections to...

forums.macrumors.com

Thanks a lot!! Unfortunately I can't tell from "About this Mac" since it's not powering up at all. I'll have a look at the serial number. From my research it looks like the backpanel is the culprit for no power up (since I already tried the PSU). Do you know how the jumper the on button to see if it powers up that way? Thanks again!

 

[tsialex]

Thanks a lot!! Unfortunately I can't tell from "About this Mac" since it's not powering up at all. I'll have a look at the serial number. From my research it looks like the backpanel is the culprit for no power up (since I already tried the PSU). Do you know how the jumper the on button to see if it powers up that way? Thanks again!

Apple Technician Guide for your Mac Pro has all the info, just follow the troubleshooting steps.

 

[Kelinu]

Quick question... so i'm following the Tech guide and I'm doing a minimum configuration test (please note I have basic knowledge in this sector and can't find any decent local help). In point number 2 it states "NOTE: OVTMP CPUA (...) CPUB LEDS on a properly functioning MP will also momentarily flash red immediately after the MP is disconnected from AC power." So mine flashes when I plug in AC mains but doesn't flash when i turn off. Do you know what this indicates as I can't find any further reference to it the guide if the LED doesn't flash on the OFF state. Thanks.

 

[tsialex]

Quick question... so i'm following the Tech guide and I'm doing a minimum configuration test (please note I have basic knowledge in this sector and can't find any decent local help). In point number 2 it states "NOTE: OVTMP CPUA (...) CPUB LEDS on a properly functioning MP will also momentarily flash red immediately after the MP is disconnected from AC power." So mine flashes when I plug in AC mains but doesn't flash when i turn off. Do you know what this indicates as I can't find any further reference to it the guide if the LED doesn't flash on the OFF state. Thanks.

If when you press DIAG button you don't have EFI DONE lit, you have a brick.

EFI DONE usually is lit even when the PSU are failing.

 

[Kelinu]

When I press DIAG (while plugged into mains only; remember that my MP doesn't turn on at all), I only get the 5V STBY amber light.
Sorry but what do you mean by "you have a brick" and where is the EFI DONE LED?

 

[tommy chen]

When I press DIAG (while plugged into mains only; remember that my MP doesn't turn on at all), I only get the 5V STBY amber light.
Sorry but what do you mean by "you have a brick" and where is the EFI DONE LED?

here you see all LEDs (whereby not all are equipped with LED at shipping!)

if the EFI done not lit then the bootROM and therefore the backplane is defective.
if it is only on the SPI chip (where the bootROM is stored),
then you can flash a new with a newly assembled bootROM and replace it.

 

[Kelinu]

Hey guys, me again; so I'm at point number 5 from the Minimum config test. (i.e., everything out and disconnected apart from empty tray and PSU - still no power up when jumpering the SYS_PWR pads in point 7. Do you think it's the motherboard (backplane) that's faulty in this case?... (Since i'm without processor and RAM installed and MP is still dead). Thanks for your all help as always...