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Valdaquendë

macrumors regular
Original poster
Nov 7, 2018
113
48
Oregon, USA
I am working on a MacBook Pro (4-TB ports, 2020) that came in able to boot about 1/3 of the way through the progress thermometer. I performed a PRAM reset (it will only chime once; attempts to perform a 2-chime or better reset produce no result; the laptop goes to the boot progress thermometer after the first chime). After the reset, I managed to boot into the recovery environment and perform a disk repair, whereupon it started booting normally. Booted it several times and logged into the client's user profile without issue. That was last night.

I came in this morning, however, and booted it again to make sure that all was well. Instead, I found that the MBP had reverted back to its "boot-one-third-of-the-way" state. Again, I performed a PRAM reset and attempted to log into Recovery Environment but found that device would not do so. I tried connecting a ProToGo16 USB drive and attempted to boot from this but found that, after choosing the USB device, the MBP would only boot about 1/20th of the way through the progress thermometer. Tried this several times; then removed PTG16 and attempted to boot into Recovery Environment but found that the syndrome repeated.

Consulted Apple's knowledge base, which advised me to perform a reinstall of the MacOS (Monterey) but I cannot boot into the Recovery Environment so could not do so.

At this point no matter what is attempted, the system will not boot further than about 1/20th of the boot progress thermometer’s length. After an appreciable time, the screen goes black. The system continues running but screen is black and there's no sign of activity. It remains in this condition until the system is powered down by pressing the power button for 10 seconds.

I can think of nothing else to try. I'm inclined to think that either the storage component or the logic circuitry (or both) are at fault. And due to Apple's decision to embed both storage and RAM into the logic board it doesn't seem to matter which component is at fault. The result is the same; basically a non-functional logic board.

The nearest Apple Store is almost 100 miles from here and I'm wondering, given the severity and intractable nature of the symptoms, whether they wouldn't just come to the same conclusion that I have; that a logic board replacement is called for. The device is well outside its 1-year warranty but could be sent in to an Apple Service Center. Or I could just get another logic board (≈ $500-$850) and replace it.

If anyone out there has seen anything like this and knows of some expedient that could yet be tried, I'd be very grateful. Or if anyone has sent in a similar device in need of a logic board for out-of-warranty service, I'd appreciate knowing what it wound up costing. Apple's support page is understandably vague and I'm trying to figure out what the best route for my client's situation would be.

Thanks in advance for taking the time and energy to read and consider this ... and thanks very much for any advice or insight you may have.
 

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Thanks, BanditoB! Yes I did try that when I tried to reinstall MacOS Monterey. The MBP went black-screen and unresponsive partway into the install and stayed that way all night. I finally reset it at noon the next day, as it was obviously going nowhere, and tried installing from USB install media but that did not work either. Not long after these attempts, I started getting the "freeze-after-a-tiny-fraction-of-load" behavior shown in the photo above. So now I cannot get to the Recovery Environment or perform any action that depends upon it.

I CAN use 'Option' to boot to the startup disk screen but no disk chosen will make any more progress than shown above. I have tried a USB drive Catalina installer, a USB drive Monterey installer and the ProToGo16 boot USB drive, all to no avail. These drives DO mount properly on other Macs in my office.
 
Unfortunately, that all points to some sort of hardware failure. Even though it's far away, I'd take it to an Apple Genius for a diagnostic. There's no cost for this other than your time and gas. Or, as you say, start looking for a new motherboard. You seem to have done all that you can do.

As a last ditch effort, you could try a DFU recovery using Apple's Configurator 2. You'll have to have another Mac available to do this, however.
 
I checked on the Apple Configurator but found that this device is not on the required list; the Configurator requires MBPs that are 2021 or 2022 models. There are two exceptions; both are 2020 MBPs with M2 CPUs (this one is Intel). As this device does not fit any of these requirements, I have to assume that it won't work.

I have searched for logic boards for this model but have found only a handful of candidates (like 3), all of them used, which range from $650 to $850 in price. I also chatted with Apple Support, which walked me through performing an internet forced-reinstall but, of course, that produced the same result as last time, at which point they suggested that I take it in for inspection.

I admit, I am tempted to do just that, but we're basically talking 1/2-day's professional time to do so and the very likely prospect (extremely likely, I'd say, since Apple Support couldn't ferret out a solution) that they'll come to the exact same solution we have. If I can scare up a few errands in that area, I may do it anyway, just to be thorough.

In the meantime, I also checked for logic board repair services and found one called BrickFence, which claims to be able to fix an A2251 logic board for $149.00 with a 90-day warranty. They appear to have record of almost 10,000 board repairs (MOBO's, GPUs, etc.) with a 100% satisfaction record on eBay. Though I may, as I said, take the MBP in for inspection, I'll probably have the board repaired. If a used board costs $650-$850 on the open market, it's hard to imagine that a new one would cost less when provided by Apple (though if anyone has any other perspective, I'd love to hear it). And then there are the fees for removal/replacement, as well.

If anyone has any experience with BrickFence or any other board repair service that you found reputable and got a quality, lasting repair from, I'd very much appreciate knowing about it.

Again, Thanks, BanditoB!
 
I checked on the Apple Configurator but found that this device is not on the required list; the Configurator requires MBPs that are 2021 or 2022 models. There are two exceptions; both are 2020 MBPs with M2 CPUs (this one is Intel). As this device does not fit any of these requirements, I have to assume that it won't work.
Are you sure? According to Apple, 2020 13-inch Intel MBP has T2 security chip (https://support.apple.com/kb/SP819, https://support.apple.com/en-us/HT208862).

iBridge firmware of T2 may have failed. Try re-flashing it using another MBP with Apple Configurator 2. You'll have to buy another MBP from Apple for this procedure if you don't have a spare one lying around. But! You can return the new one for free after you're done with Apple Configurator. Just make sure to return it in under 2 weeks!..

P.S. 2013 13-inch M1 MBP has 2 Thunderbolt ports, and it doesn't have T2 security schit. However 2013 13-inch Intel MBP with 2 Thunderbolt ports has T2 SS.
 
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Thanks, tinygoblin! Your remarks led me to perform more research, leading to this article which explains the procedure for reviving an Intel-based Mac (including the affected MBP) from another Mac (not necessarily an MBP). I am going to try this in the next day or two and will report the results in this thread.

Again, thanks!
 
First, my thanks to both BanditoB and tinygoblin - You both gave me valuable tips that, while they don't seem to have solved my particular problem, gave me valuable insights and led me to new (to me) tools and knowledge.

I have tried the procedure set forth in Apple's "Revive/Restore an Intel Mac using Configurator" article, using a Late 2019 iMac which has 2 Thunderbolt 2 ports and 4 USB ports, as the "host" . I managed to boot the "client" (a 2020, 13" Intel MBP) into DFU recovery mode, in spite of directions on the Apple Configurator support page which were, in my experience, inaccurate.

For those who may have trouble booting into DFU reset mode using Apple's instructions, I found that powering up and holding down "Left-Ctrl + Left-Opt + Right-Shift" for the three seconds prescribed in the article did not cause a DFU boot. What worked for me was:

1) Position your fingers to press all of these keys
2) Press the power key and hold it down
3) After 1 second, keep pressing the power button and press "Left-Ctrl + Left-Opt + Right-Shift" for ABOUT TEN SECONDS

This worked every time I tried it

I performed a System Revive (the non-destructive option with respect to the client's data) which appears to have reset the T2 security chip's instructions and caused the MBP to boot with a flashing boot-folder icon. I noted that, although Configurator appeared to perform correctly and displayed the locked "Apple Controller" icon at the conclusion of the recovery, the laptop did not reboot as the documentation led me to expect.

Then I rebooted manually, using Internet Restore (Cmd-Opt-R). The system software appeared to download and install but at about 35 minutes, the screen simply went blank. I waited for another hour, thinking that things might be taking place under the hood without outward sign, and then rebooted. It displayed the flashing boot-folder icon again. I tried installing two more times, waiting as long as two hours for install time. Then I went back to the Configurator and chose System Restore; this option is destructive to the user's data and is, as far as I know, the "final court of appeal" when it comes to system restoration.

The results were the same as with System Revive; a recursive flashing boot-folder icon no matter how many times the Internet Restore option is executed.

At this point, it seems clear that either the T2 chip or, more likely, the storage, in the laptop, is defective; I think the storage hypothesis best explains the behaviour. The T2 security chip seems to reset properly (according to Configurator) and the system is capable of downloading the software but when it attempts to install, the process hangs or aborts.

This highlights the frustration that so many of us feel at Apple's switch to soldered-in and integrated (read: unrepairable) components; had this been an M.2 or other discrete storage device, a simple replacement could have been performed in under an hour. As things stand (and assuming that no one can suggest any other expedient), we are looking at shipping the logic board off for troubleshooting/repair.

At any rate, the bottom line seems to be "off to the logic board repair service". I expect to send the board off early next week. I'll report back on my experience with the BrickFence logic board repair service.

Thanks again, BanditoB and tinygoblin, for your insights.
 
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An added note: I contacted several board repair services and was told that, if the issue is in the NAND (flash storage) circuitry, the board is unrepairable and must be replaced. I rather suspect that this is the case, given the symptoms above, but will send it off anyway, as they charge nothing more than return shipping for diagnosing an unrepairable board.
 
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