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Mac Pro 2013 (trashcan) 10.15.2 - USB fails after about 45 seconds..

First, I've looked all around, but cannot see an answer..


I bought a used Trashcan Mac Pro last week, 12GB RAM, 256GB SSD, 'Catalina' (which I've since upgraded to 10.15.2).


With its earlier version of Catalina, it would originally freeze the USB Apple (Final Cut Pro style) keyboard & USB Apple mouse, and also bluetooth & wi-fi, within about 45 seconds of startup ..and the USB k'bd and mouse froze even when connecting them via a Thunderbolt USB hub. Every time. I reset NVRAM, power management, tried Safe mode, Diagnostic mode, Reinstall mode, trashed all Preferences, with no results except that Safe mode extended the delay before freeze to about 2 mins, and Reinstall mode to about 25 minutes, but that precluded a full OS download to reinstall the OS!


The INNARDS of the computer CONTINUED to work, as shown by a continuously updating Terminal window ..it was just the peripheral connections - except the screen - which froze.


I took it back to seller, who fiddled with it, but didn't know what they'd done to make it behave except that they'd reinstalled the OS to 10.15.1 ..and it did then behave. I took it home again, and deleted the original User after creating New User for me. All was perfect!


A message appeared that I could upgrade to 10.15.2 ..which I then did, as the keyboard & mouse stayed active OK during the 45 mins or so which it took to upgrade.


AFTER the upgrade to OS 10.15.2 the original problem has reappeared: k'b and mouse freeze after 45 seconds, except when running in Safe mode, no matter how many reboots I do.


I wondered if any of this is connected in some way to the teeny circular battery - ALMOST available behind the sockets at the rear of the machine, but whose replacement involves COMPLETE dismantling & reassembly (see online iFixit teardown to replace MacPro battery) - or if the battery has nothing whatever to do with freezes, but then what is it for ..does anyone know? I find no mention of it, or its purpose, in any Apple support documents.


I have opened the window, ready to hurl this trashcan to the street, but would appreciate (1) any experience of this problem and its solution, or (2) any INFORMED suggestions as to how to fix this freeze before all my hair's torn out.


Yours appreciatively in advance,


David.

Mac Pro

Posted on Dec 15, 2019 5:05 AM

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Question marked as Top-ranking reply

Posted on Dec 18, 2019 3:19 AM

In case anyone else is having - or has had - similar problems, here's how I (..so far, anyway..) fixed it:


I found - by looking things up online - that the little 'CMOS battery' is there just, apparently, to maintain the date and time when the Mac's off. But my date & time weren't failing; they were always OK ..so: not the tiny, almost inaccessible 'CMOS battery'.


I decided that this appeared to be a breakdown between external devices (mouse, keyboard, wi-fi and bluetooth systems) and the DISPLAY ..that's to say graphics cards.


iFixit's demo of how to reach the 'CMOS battery' shows - on the way to the battery - the removal of the connections between the interconnect Board at the very bottom of the trashcan Mac Pro and the graphics cards. The connection is a flat multi-pin cable at the very bottom of the machine, but easily accessible as soon as the cover's been lifted off. I thought that perhaps this connection may have been insufficiently tight (..it may have been disturbed by moving the Mac, or general knocks and bangs, or just not made tight enough at original assembly).


I also decided to re-upgrade the OS software BY ETHERNET CABLE, instead of trying to use wi-fi (which disconnected after 25 minutes).


So I opened the case - it took 5 seconds to lift off the cover - then prised off the graphics cards' connections (the flat black connectors at the base of the graphics cards), then FIRMLY re-attached those multi-pin connector cables, put back the cover, plugged in an Ethernet cable, waited for 5 seconds - after re-inserting the mains cable - before re-booting (to reset the power management system), restarted holding down command+alt+P+R to reset Parameter RAM, then shut down, then restarted with cmd+R in 'Restore' mode, and re-downloaded the latest (10.15.2) 'Catalina' OS.


The machine ran perfectly during download and installation and then restarted ..and has now run perfectly ever since, including sleep, wake, power down, restart, etcetera, and seems PERFECTLY stable.


It appears that either - or both - FIRMLY reconnecting the graphics cards plus re-installing the latest OS has fixed my - and perhaps your - problem.


Thanks to iFixit Tech Support for clarifying exactly what the 'CMOS battery' does (and doesn't) do. I haven't found any other documentation which explains what this problem might be, or how to fix it, so I hope this helps!

Similar questions

2 replies
Question marked as Top-ranking reply

Dec 18, 2019 3:19 AM in response to David Babsky

In case anyone else is having - or has had - similar problems, here's how I (..so far, anyway..) fixed it:


I found - by looking things up online - that the little 'CMOS battery' is there just, apparently, to maintain the date and time when the Mac's off. But my date & time weren't failing; they were always OK ..so: not the tiny, almost inaccessible 'CMOS battery'.


I decided that this appeared to be a breakdown between external devices (mouse, keyboard, wi-fi and bluetooth systems) and the DISPLAY ..that's to say graphics cards.


iFixit's demo of how to reach the 'CMOS battery' shows - on the way to the battery - the removal of the connections between the interconnect Board at the very bottom of the trashcan Mac Pro and the graphics cards. The connection is a flat multi-pin cable at the very bottom of the machine, but easily accessible as soon as the cover's been lifted off. I thought that perhaps this connection may have been insufficiently tight (..it may have been disturbed by moving the Mac, or general knocks and bangs, or just not made tight enough at original assembly).


I also decided to re-upgrade the OS software BY ETHERNET CABLE, instead of trying to use wi-fi (which disconnected after 25 minutes).


So I opened the case - it took 5 seconds to lift off the cover - then prised off the graphics cards' connections (the flat black connectors at the base of the graphics cards), then FIRMLY re-attached those multi-pin connector cables, put back the cover, plugged in an Ethernet cable, waited for 5 seconds - after re-inserting the mains cable - before re-booting (to reset the power management system), restarted holding down command+alt+P+R to reset Parameter RAM, then shut down, then restarted with cmd+R in 'Restore' mode, and re-downloaded the latest (10.15.2) 'Catalina' OS.


The machine ran perfectly during download and installation and then restarted ..and has now run perfectly ever since, including sleep, wake, power down, restart, etcetera, and seems PERFECTLY stable.


It appears that either - or both - FIRMLY reconnecting the graphics cards plus re-installing the latest OS has fixed my - and perhaps your - problem.


Thanks to iFixit Tech Support for clarifying exactly what the 'CMOS battery' does (and doesn't) do. I haven't found any other documentation which explains what this problem might be, or how to fix it, so I hope this helps!

Dec 16, 2019 12:53 AM in response to David Babsky

I've found - with more hunting - that this was a known problem with the trashcan Mac Pros which had AMD D500 and D700 graphics cards, and that Apple initiated a Repair Extension Program for these, offering to swap those graphics cards for replacements. But the AMD FirePro D300 GPUs - which this particular trashcan has - were NOT included in this replacement program, as they were thought to be unaffected.


As the keyboard and mouse do become ACTIVE again - very briefly - if the trashcan's DISPLAY is allowed to sleep and is then awoken, it may, indeed, be a graphics problem ..or at least a problem with *external* devices communicating with the graphics system ..although that wouldn't, I suppose, explain the temporary cutting-out of the bluetooth and wi-fi systems.


Maybe the graphics cards need re-seating in their slots (?) ..I'll give that a try.


Any other ideas anyone..?


Thanks in advance.

Mac Pro 2013 (trashcan) 10.15.2 - USB fails after about 45 seconds..

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