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kirreip

macrumors regular
Original poster
Feb 11, 2009
155
33
I have a Mac Pro (4,1 --> 5,1) which was working fine until yesterday.

When I came home after work yesterday, I realized that we had suffered a power failure sometime during the day (for how long I cannot say, also what could have been the reason).

My Mac Pro was off and connected to a UPS when I left home.

When I wanted to start the Mac Pro today, that did not work. I pulled out all the cables and waited about 20 seconds. Then I tried again (on the UPS) and it still did not boot. So I pulled off the power cord again and connected to a normal power outlet. After that it started normally. But since then, one USB port on the back does not work anymore, no matter what I try.

I did SMC and PRAM reset, but to no avail.

Do you have any other ideas, what I could try?
 

tsialex

Contributor
Jun 13, 2016
12,875
13,112
I don't know if Mac Pro has regenerative fuses, but some devices has them and after some time, a day or two, the fuses restore itself. Maybe leave the port alone for 48 hours, then test again.
 

crjackson2134

macrumors 601
Mar 6, 2013
4,822
1,947
Charlotte, NC
I have a Mac Pro (4,1 --> 5,1) which was working fine until yesterday.

When I came home after work yesterday, I realized that we had suffered a power failure sometime during the day (for how long I cannot say, also what could have been the reason).

My Mac Pro was off and connected to a UPS when I left home.

When I wanted to start the Mac Pro today, that did not work. I pulled out all the cables and waited about 20 seconds. Then I tried again (on the UPS) and it still did not boot. So I pulled off the power cord again and connected to a normal power outlet. After that it started normally. But since then, one USB port on the back does not work anymore, no matter what I try.

I did SMC and PRAM reset, but to no avail.

Do you have any other ideas, what I could try?

What OS are you using? I’ve seen multiple instances where a single USB port stopped working, and it turned out to be software issue (virtual USB driver bug/corruption or equivalent, presumably).

Download a bootable live-Linux ISO (I use Ubuntu) and check from there. This can happen to both the built-in USB ports and to PCIe cards as well. Give it a try before condemning the port as dead.
 

bookemdano

macrumors 68000
Jul 29, 2011
1,512
843
Was something plugged into the port that died? And if so, does whatever was plugged in there still work?

I think the other suggestions you got from tsialex and crjackson are spot on. If it doesn't work after that then I think it is dead indeed. You might consider installing a USB 3.0 or 3.1 card anyway as you can definitely get faster transfers that way and drivers are built-in for a bunch of cards now.
 
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kirreip

macrumors regular
Original poster
Feb 11, 2009
155
33
I don't know if Mac Pro has regenerative fuses, but some devices has them and after some time, a day or two, the fuses restore itself. Maybe leave the port alone for 48 hours, then test again.

Okay, I will give it another shot in a few days.

What OS are you using? I’ve seen multiple instances where a single USB port stopped working, and it turned out to be software issue (virtual USB driver bug/corruption or equivalent, presumably).

Download a bootable live-Linux ISO (I use Ubuntu) and check from there. This can happen to both the built-in USB ports and to PCIe cards as well. Give it a try before condemning the port as dead.

I have 10.13.6 installed. Actually, I have Windows 10 on another drive. I will try the port in a few days when booting into Windows 10. And I have some live-Linux DVDs around and I will try that too.

Was something plugged into the port that died? And if so, does whatever was plugged in there still work?

I think the other suggestions you got from tsialex and crjackson are spot on. If it doesn't work after that then I think it is dead indeed. You might consider installing a USB 3.0 or 3.1 card anyway as you can definitely get faster transfers that way and drivers are built-in for a bunch of cards now.

Yes, my keyboard was plugged in that port. It still works when plugged in the other ports.

If it's dead, I might consider a USB 3.0 or 3.1 card. But first, I have to decide which Metal capable GPU I buy for Mojave (still waiting for boot screen, Apple... :rolleyes: but that's another story).


Thanks for all your suggetions, highly appreciated!
 

thornslack

macrumors 6502
Nov 16, 2013
410
165
If you have windows you could check in the device manger and see if the hardware is reporting anything.
 

Mad Davey

macrumors member
May 22, 2017
63
16
Same issue 4,1 to 5,1. It's the top front USB port. I changed the USB board and connector to motherboard with no joy. I changed the battery as suggested in another thread, no joy. Tried booting another drive with another OS, no joy. Oh well. I suspect Windows would not be any different.

On my 5,1 I intentionally removed the top USB port and changed it with one from an internal USB 3.0 card while leaving the lower one hooked up normally for USB booting. The Mac USB boot selector will not see the boot disks when hooked to my USB 3.0 card. I guess I'll be doing that mod again, it wasn't easy but it's nice to have USB 3.0 in the front instead of hub taped on top.
 
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