Mac Pro 5,1 rear USB ports failure - still faulty!

[ibarnett]

Yesterday suddenly couldn't type. Was OK when I booted & for several hours.
Rebooted, no change.
Moved keyboard (wired) to all rear usb, still nothing.
OK, from front ports & USB 3.0 & USB 3.1 cards.
Nothing works from rear USB ports.
Tried (several times) SMC reset & NVRAM reset, no change.
Apple Technician Guide is really helpful
"Backplane board failure, replace backplane board"
Now using bluetooth keyboard, which I can live with, but does anyone have any other ideas???
Cheaper (nearly) to buy secondhand Mac Pro rather than backplane board.

 

[bsbeamer]

Almost always cheaper to buy a used unit as close to "barebones" and use that as part replacement. Also gives you options in case there is another part that also may need to be replaced, or becomes damaged during replacement.

 

[rpmurray]

Have you tried testing it from a Safe Boot?

 

[crjackson2134]

Remove/Disconned our current drives.
Put in a temporary scratch drive and install a fresh copy of macOS.
Don’t install any other software at all.

Test you newly installed macOS and see if you still have the USB problem.

If you determine a backplane is needed;
A replacement backplane board can be had for about $75 US if you shop wisely on ebay. If you don’t see one that cheap right away, you may need to wait a bit. I purchased mine for $67 (2012) and another one for $140 when I was in a hurry.

If you can live with it (I couldn’t) nagging at you, just use the front ports when you need to access the command key-combinations during boot. Otherwise use the add-in card and a hub. This is the easiest and cheapest way to go.

If you decided to go the route to replace the backplane, don’t jump in until you let us know, so that you can get prepared for the firmware upgrades you’ll likely need.

 

[JronMasteR]

If you decide to replace the backplane board, make a rom dump before.
It is not easy to find a "blank" board (one which has never been used before).
Otherwise you might end up with severe issues.

If it has been used before, there is the old serial number etc. on it, so you might get into trouble with imessage and such

 

[Macschrauber]

you can dump your Rom and write it to the "new" board

 

[ibarnett]

Thanks everyone for your info.
This morning whilst thinking the course of action I had one more try.
Connected an old Apple wired mouse to the front ports to make sure it was still working, it was, both the mouse & front ports.
Then connected to the rear ports, & behold all working.
Then the keyboard as before & it also works, & still working after 5 hours.
Apart from the stuff I tried above, I came across this post:
https://forums.macrumors.com/threads/mac-pro-front-usb-ports-not-working.231251/#post-26828155
Which states, post #24:
"For the tower you have to replace the battery behind the Graphics Card that keeps time for the clock when it's switch off. It's a disc type called a 2032. You can find them anywhere next to the watch batteries. A forum had this answer and it worked for me. I know that sounds strange, but it did the trick. For some reason that battery has something to do with running the USB ports"
It didn't work when I replaced the battery plus another NVRAM reset, however now working.
I must admit I really don't understand why???
Will leave the Mac running all day just to double check it's not something else, heat related or whatever.
The problem returned - after running all day the fault had returned by the time I got hope.
So back to more fault finding as suggested above.
I will report back.

 

[ibarnett]

OK, I have now finished trying everything I can think of, plus all the suggestions above, as well I have cleaned from all internal dust.
The situation now:
The 2 outer rear USB ports don't work at all, the inner port works sometimes.
By sometimes:
Sometimes works at startup, & keeps working.
Sometimes works at startup then fails after several hours.
Sometimes doesn't work at all.
Now using Bluetooth keyboard, which I either have to live with, or go Mac Mini.
My requirements these days would make the Mini adequate, there are still some 2014 in the Refurb Store but I wonder about their life of OS updates?

 

[crjackson2134]

OK, I have now finished trying everything I can think of, plus all the suggestions above, as well I have cleaned from all internal dust.
The situation now:
The 2 outer rear USB ports don't work at all, the inner port works sometimes.
By sometimes:
Sometimes works at startup, & keeps working.
Sometimes works at startup then fails after several hours.
Sometimes doesn't work at all.
Now using Bluetooth keyboard, which I either have to live with, or go Mac Mini.
My requirements these days would make the Mini adequate, there are still some 2014 in the Refurb Store but I wonder about their life of OS updates?

Did you boot into another OS disk and see if the same occurs? I find that downloading and making an UBUNTU LINUX disk for booting and testing is a great tool.

Try this and if after boot up, the same ports are dead, your USB I/O header is probably borked. From there, you can either live with it by using a USB Hub, or a USB PCIe card, or replacing the LogicBoard.

That's all I've got.... Good Luck...

 

[bsbeamer]

Sounds like physical issue vs. software, but can also try a clean install of macOS (even earlier versions) onto a separate drive, just to eliminate corrupt .kext or similar issue. Does not happen all that often, but some base kexts/components/extensions can be corrupted when migrating/importing from another system drive. You can also try repairing all permissions in case somehow something became locked. Also running maintenance scripts as last resort.

 

[ibarnett]

I did the clean MacOS, but I haven't tried different OS.
I will try the Ubuntu this week.
Thanks.

 

[crjackson2134]

I did the clean MacOS, but I haven't tried different OS.
I will try the Ubuntu this week.
Thanks.

If you did a truly clean/virgin install without adding any apps or migration, and still have the exact same issue, I'd say you've accomplished the same thing. A UBUNTU disk would've been faster, but it seems you've already proven that it's hardware if what I said above is accurate.

It sounds like it's decision time... Logicboard, Hub, or PCIe card. Since I'm somewhat OCD about things in general, I'd go with a logic board personally.

 

[tsialex]

I did the clean MacOS, but I haven't tried different OS.
I will try the Ubuntu this week.
Thanks.

The backplane has a lot of SMD fuses that protect the USB ports, some of these fuses are self-repairable to some extent.

If the short circuit that caused the SMD fuses to stop working was a weak one, the fuses will work again after some time, usually 36 to 48H without any power. This has a limit, after some self-repairs the fuses blow for real, then it's necessary to replace the backplane, or if you have the equipment and ability, the SMD fuses.

BTW, every time you connect an USB device, a little short-circuit happens at the moment of insertion, so, you are always short-circuiting the backplane. The fuses work to prevent that these little ones do any damage, after years of normal usage these little shorts cause cumulative wear on the fuses.

 

[ibarnett]

Thanks tsialex.
Very informative indeed.
Yes, I believe it's a hardware issue.
So, now I'm at a crossroad. Some time ago I bought another 5,1 with the idea of using for parts, however now we are using it in another room. Trouble is 1 of the rear ports, although working, is loose, or more to the point the male usb is loose when plugged in. Maybe I can cannibalise to make 1 good one, as long as I can take the USB block off 1 backplane for the other???

 

[tsialex]

Thanks tsialex.
Very informative indeed.
Yes, I believe it's a hardware issue.
So, now I'm at a crossroad. Some time ago I bought another 5,1 with the idea of using for parts, however now we are using it in another room. Trouble is 1 of the rear ports, although working, is loose, or more to the point the male usb is loose when plugged in. Maybe I can cannibalise to make 1 good one, as long as I can take the USB block off 1 backplane for the other???

If you are already using the one that you bought for parts, just buy the backplane and anything you will need to repair the parts one.

The back USB ports are part of the backplane, you can’t take it out of board without serious desoldering.

You can buy an used backplane for less than $70 on eBay US. Unless you find another Mac Pro super cheap, the way to go is another backplane.

The front USB ports are separated, a little board that is very cheap, around $10~$15. I bought one recently on a eBay promo for $25, with shipping from US to Brazil.

eBay constantly has promos, just wait for one, you can still use your Mac Pro with the bad USB ports.

 

[ibarnett]

Yes, I can see now ports not easily separated from backplane.
Can't see at the moment anything less than $300 Australian on eBay, & another second hand complete here $1000 plus, so not feasible .
Will just keep these 2 units going as I have invested so much time, money, & fun in them.
Can't see me with an iMac, a Mac Mini will eventually be a better option, but no fun
The new Mac Pro, whenever it lands, will be just too expensive for me!

 

[ibarnett]

Ok, just to report further.....
I have 2 2010 Mac Pro's, & in my wisdom (?) I have decided to move on.
1 is selling on eBay ( not the problem child!), I have a bid @ fairly sure the sale will complete, just a matter of what price, but I am reasonably happy with the progress.
Now in this process I am selling lots of bits & pieces.
Amongst this is about 6 Graphics adapters, I checked them all in the problematic machine, & checked again after replacing current card, & booted up OK a few days ago.
Now, when I went to start the Mac Pro today - nothing - no lights, spin up, just zilch. Checked power source etc.
Reseated graphics card & it did restart, however only one front USB port working.
Now thinking of dismantling & selling the parts, rather than advertising faulty machine.
UNLESS someone has an idea to fix, I'm not going to replace backplane BTW.