Mac Pro Tower 2019 Will Not Boot

Question

Level 1

4 points

Mac Pro Tower 2019 Will Not Boot

Was Running perfect (Sequoia). I added a USB-C extension cord for my second monitor and then went to turn it on. The computer would not boot. I then removed the USB-C extension and tried again. Nothing. The light will come on, no chime, and then goes off. I've tried everything. Even replaced the memory, unplugged all peripherals, changed the plug, tried "Shift, Option, command" (Reset SMC). None of it worked. I can't believe the extension cord did this. I am very baffled. To make matters worse, there is not a Mac Service person within 100 miles and I have a looming deadline.

I did try a different monitor and actual saw the Apple logo briefly. It then turned off.

Mac Pro, macOS 12.7

Posted on Jan 21, 2025 2:18 PM

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Answer 1

varjak paw

Level 10

181,396 points

Jan 21, 2025 2:24 PM in response to noisegate1

It's possible that when you connected the USB cable your Mac got a static shock which could have caused damage. If so, then service would be required. But perhaps there will be something in this support document or in the links it contains that you haven't tried:

If your Mac doesn't turn on - Apple Support

Someone else here may have additional suggestions I can't think of to suggest right now.

Regards.

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Answer 2

Jan 21, 2025 4:39 PM in response to noisegate1

Replacing or adding to the memory in a 2019 MacPro tower is VERY complicated. There should be some complicated charts, and they must be followed exactly. you can't just Add memory to that model -- adding memory may require that you re-arrange all the modules.

Install and replace memory in your Mac Pro (2019) - Apple Support

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Answer 3

noisegate1 Author

Level 1

4 points

Jan 21, 2025 2:40 PM in response to varjak paw

Thank you Varjak for the quick response. I suppose I may have introduced static but in our area, the humidity runs about 70% so we normally don't have this issue. That said, anything is possible - perhaps there was static in the line???. I imagine that is a possibility. I did previously go through everything listed in the link that you attached...even went as far as replacing the memory (I just upgraded the memory a few weeks ago). Maybe I'm doing something wrong.

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Answer 4

noisegate1 Author

Level 1

4 points

Jan 21, 2025 3:30 PM in response to noisegate1

After doing a bit of research on Pram batteries, I came upon someone else's suggestion as follows:

Remove AC power cord.

Press the power-on button for a quarter minute. This completely depletes the power capacitors, taking all Voltages inside to Zero except the PRAM backup battery.

restore AC power cord

wait a quarter minute.

Power on as usual.

After following these instructions, the computer powered up and came to life! I did get a Panic Medic Boot message that stated "A third party kernel extension was preventing the machine from successfully booting." I have no idea what that means.

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Answer 5

noisegate1 Author

Level 1

4 points

Jan 21, 2025 4:14 PM in response to noisegate1

Of course...another issue. When the machine did power back on and seemed ok, I turned it off, replaced the old memory with the relatively new memory and I got a flashing amber light when I attempted to power on the machine. I then put the old memory back in, and the machine powered right up. Adding to the mystery, I am now getting software conflict notifications...Printer software/Wacom Tablet software not compatible. I wasn't having any trouble with this before.

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Answer 6

noisegate1 Author

Level 1

4 points

Jan 21, 2025 4:52 PM in response to Grant Bennet-Alder

Honestly, when I replaced the memory a few weeks ago, it did not seem that complicated (and yes, I did read and follow all the instructions). I had 6 original DIMMs (8 GB each) and they were replaced with 6 DIMMs (32 GB each) in the same slots - no struggle. The new memory was working fine.

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