• PFM006 - There may be an issue with the System Management Controller (SMC)

• PPM001 - There may be an issue with the power management system

The mac powers on fine, but is extremely slow. The SSD is cleared so no software is installed, running from Big Sur from an USB is also really slow.

I’ve opened up the machine and there was a lot of dust. Cleaned out a lot and have put it back together. No change. The water indicators I’ve seen on the boards are not red, hence there is no liquid damage from what I can see. Nor can I see anything weird on the open sides of the boards.

I’ve also done the SMC reset, didn’t help either.

I got the 6 core D500 model with 16gb ram. It also has some HDMI issues from time to time, having the screen flicker (like it’s not getting a propper connection); however using thunderbolt > HDMI works fine.

Does anybody know what I can do to resolve this issue? Do I need to replace the backpanel/PSU, or is there another issue which I can look at?

⟐ Answer edited August 25, 2025 at 10:08 MST

⟐ Commented February 24, 2026 at 12:32 MST

as you are the experts in the field — my Mac Pro exhibits some audible coil whining. I've tried unplugging all kinds of devices and ran the device through another power outlet. I've disabled Bluetooth and WiFi to change power consumption. I've changed the fan speed with iStat menus and tried putting some strain on the GPU and CPU with benchmarks. The noise stays the same: http://cl.ly/3c032O0R3v2a

Any ideas or would you say the noise is within spec? Apple would exchange the nMP for a new one but they are not sure if that would fix the issue...

⟐ Answered May 03, 2022 at 0:15 MST

⟐ Commented August 30, 2023 at 17:02 MST

Customer reported that the system had randomly powered off by itself a few times before it finally wouldn’t power on any more.

Currently when power button is pressed there are no lights, no clicks, nothing. I already tried an SMC reset and replaced the CMOS battery, not because I thought they would work, but mostly to check the boxes and hope for a lucky break.

At this point I’m pretty sure it’s either the logic board or power supply, with my gut saying it’s probably the power supply. Unfortunately I don’t have spare parts to test with to confirm which is faulty. Is there any way to test voltages on the power supply to determine if the power supply is dead or short pins to power it on?

⟐ Answer deleted July 23, 2021 at 12:25 MST

Note I also posted is also on another site and I’m gonna include everything with yesterday’s updates at the end.

I replaced the GPU on my Mac Pro 2013 and while doing that I replaced the thermal paste for the CPU too now the computer is not powering on ( No POST ) I have the lights on except the power button light is off .. first I thought it's something with the new refurbished GPU but it's not because I tested it with another working GPU.

• The battery inside needs a replacement ( I did a replacement with no luck. )
• The power supply is not working ( I can see the red light after hocking up the power cable ( Without the logic board installed if the logic board is connected to the riser the red lights in the logic board and the PSU will go off as normal behavior ) I also get the green light when I press the little check button on the I/O board from the inside ( more details about this at the end ) then I used the multimeter to measure the power that it's going to the CPU riser and it's giving me 1V .. I don't know if it's the right number.
• The logic board got damaged? but why? everything is fine also it's red light is on when it's connected to the PSU only .. it's not my first time disassembling the Trash Can and I did it so many times and I even looked at the sensitive data cables that connect the logic board to everything I can't see any broken pins.
• Someone said press shift on the keyboard while turning on the device but I’m using a USB keyboard and there is no power on the USB ports ! the screen wakes up though pressing the power button (connected via thunderbolt )

Finally, I always take precautions like wearing an anti-static bracelet and not using any screwdrivers with magnets also changed the power cable connected it directly to the wall

Please help .. Thanks

TL,DR : I/O lights On except the power button No Chime No Fan Just the Lights for 15 sec then they go off .. PSU seems fine ( I might be wrong ) .. I put the older GPU back, replaced the battery with no luck.

UPDATE #1 :

I followed this guide ++https://logi.wiki/index.php/Mac_Pro_6,1_...

I got #2 & #5 on while the computer is off .. will try to do power on without the lid I just need a magnet that I don't think that I actually have at the moment

UPDATE #2: I managed to find a magnet and activate the computer power without the cover being on ( if you wanna do it too just stick the magnet next to the power button outside the seam. )

Now thankfully I got all the Diagnostic LEDs on Green Light Except the first one which means everything is working !!!!! then why it's not POSTING !!!!?????

Also, does anyone knows how to check the CPU Riser LEDs without dismantling the whole thing and make everything dangling with a magnet stuck to the I/O it’s seems a little bit dangerous to do that?

UPDATE 3 : I just noticed that Error LEDs ( two RED ) on the logic board are on ! ... Still don't know what that supposed to mean.

Please help

Thank you

⟐ Commented October 09, 2024 at 9:15 MST

The new Mac Pro - are the RAM and SSD upgradable ?

Thanks

⟐ Answer edited December 07, 2017 at 6:41 MST

⟐ Commented April 13, 2021 at 9:11 MST

I have left it unplugged from power for 12 hours (while sleeping) and then held down the power on button for 10 secs. That did not seem to affect the bad behavior at all. Fan still at full speed.

Ran the Apple Hardware Test which is built in, and it reported there may be an issue with the SMC Power Manager. I just ran it again and it comes up with the same error message: There may be an issue with the System Management Controller (SMC) Ref. Code PFM006

HELP, I don’t know what to do now.

⟐ Comment deleted June 24, 2022 at 19:34 MST

Thanks!

⟐ Answer accepted December 20, 2024 at 12:23 MST

I would like to upgrade mine to 1TB SSD.

Thanks in advance.

⟐ Answered April 04, 2019 at 7:20 MST

⟐ Commented February 09, 2017 at 19:20 MST

thanks

⟐ Commented January 10, 2023 at 0:18 MST

⟐ Commented March 10, 2022 at 13:08 MST

⟐ Answer accepted September 28, 2022 at 6:06 MST

⟐ Commented December 05, 2021 at 4:52 MST

First time posting here so apologies if this is silly!

Mac Pro 6,1 that no longer POST’s or shows Video out. Was fine on boot and then restarted into safe mode without holding shift.

After a quick NVRAM reset Mac no longer POSTs

Tried new RAM no joy, Replaced coin battery no joy, tried all video out options, diags LED indicated bottom LED PCIE switch status flashing indicating V1 or V2 mode (been trying to find out whether this is indicating why I can’t get USB keyboard to register!)

I have tried replacing both GPU A and B but honestly there is a chance these cards are defective as well since I cannot test them currently.

Anything I am missing?

Thank you for any information that can be provided!

⟐ Commented March 21, 2024 at 16:05 MST

⟐ Commented February 06, 2021 at 20:10 MST

First, sorry for the hiatus. I've been out of the business for a while. But I'm back!

Apple couldn't tell me anything. They offered me to pay a flat $500 fee, and they would replace anything that needed to be replaced untill it worked…

I ended up just selling it for parts…

So I have a Apple Mac Pro "Quad Core" 3.7 (Late 2013) that wont power on.

I do not know the history of the machine.

I plugged it in and got nothing, no beeps. no fan spinning, no response.

I do all the normal procedures, swapped ram, tried different SSD, reset SMC, tried different power cable and outlet. None of that worked.

I took the case off and found a bright red LED shinning.

So I started searching the internet, thinking that there MUST be some information about this red LED.... NOTHING!!!

So I proceeded to take the whole thing apart, took it down to bare bones to make sure everything was connected properly and to see if I could find any corrosion from any liquid damage or such.

While I was at it I re applied thermal paste on both the CPU and GPU.

Nothing appeared to be out of place, no damage to the board, all connections were secure.

I put it back together, powered it on, and still nothing, just the red LED...

WHAT IS WRONG WITH THIS THING!?

Please, if you have any idea what could be wrong, any suggestions, or any explanation about this red LED I would LOVE to hear it.

I'm totally baffled by this one...

Thanks in advanced,

Taylor

⟐ Answered December 24, 2024 at 21:51 MST