Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

MP 1,1-5,1 Fix for Mac pro 5.1 random shutdown

Z

zcream

macrumors member
Original poster
Sep 8, 2008
52
7
I was running a GTX 1080 ti using 6pin to 8pin cable. My psu blew. That got fixed and now there is random shutdown. I swapped cpu board with another working Mac pro. Now problem is isolated to backplane board.
I am going to replace capacitors to see if problem gets fixed. There are a total of 11 caps.
4x with 024 svpe 150 16 written.
4x with 04 680 16k
These 8 are mounted on some sort of plastic tab and surface mount solder.
There are 3 others. 2x with 022 svpe 100 16 and 1x with 027 svpe 100 16 and I think these three are next to some sort of regulator.
ac9a236b93e4e2a8d208506878a9167a.jpg
cae272b82b0c042488fbbca3ffb37037.jpg
dcf4252d9053e833219f8d667c36cb6f.jpg
68d4ac39e5d464b615ef4176aab58b12.jpg
99fd85353fb73407dc2c9213cb4c7efe.jpg
 
I got no clue how to remove the caps on these plastic tabs.
So I will start by replacing the 3 caps soldered into the Mobo.
Any advice is welcome.
 
100uf 16v SVP series caps. I have the option of replacement with tantalum caps for better esr.
 
Is there any reason that you settled on just those few capacitors - when there are many others in your Mac Pro?
 
I see 11 capacitor. Only 3 of them are not mounted on a plastic tab. That's why j chose these 3. Also, next to these in an inductor 0.47uf and that's a regulator LC circuit.
 
Have you worked with the other 8 caps that's are smd and mounted on a plastic tab?
 
No, I was just wondering how you determined that just those 11 caps need replacing (and not other caps)
Best way forward is to find a shop that has board repair capabilities.
 
I don't see any other caps on the backplane board. Could you kindly point me to the other caps?
 
I had a different issue than you, but I purchased a 2012 Backplane from eBay for $70 and all is well after many months.

If you are doing this repair as an exercise in learning, then great. Otherwise, I would recommend just getting a replacement backplane.
 
  • Like
Reactions: Synchro3, DeltaMac and bsbeamer
I have some software licenses tied to the backplane. So I need to fix it. :-( don't have a choice in the matter.
 
zcream said:
I don't see any other caps on the backplane board. Could you kindly point me to the other caps?
Click to expand...
It's been some time since I have hunched over a circuit board - but just in the first picture, I see what looks like capacitors (surface mount, brown in color) may 5 within an inch of the cans that you indicated. I also think there is about 35 or more along the length of the card slot, again within a couple of inches of those cans - all in the first picture. (electronic devices come in several different forms, not just cans)

And, I agree, if you aren't too sure about how to proceed with a repair, a replacement backplane is not too hard to find.
[doublepost=1566937382][/doublepost]
zcream said:
I have some software licenses tied to the backplane. So I need to fix it. :-( don't have a choice in the matter.
Click to expand...
I'm not saying that bunch of caps won't fix your issue - but what testing did you use to decide on just those parts?
 
zcream said:
I have some software licenses tied to the backplane. So I need to fix it. :-( don't have a choice in the matter.
Click to expand...

While inconvenient, you can generally correct any problems by contacting the publishers of said software. If they are slow to respond, consider that you are currently denied access anyway while attempting to repair your backplane. I'm not sure how you pin-pointed your problems to the electrolytic CAPS, but what happens after all this trouble if it doesn't turnout to be the definitive solution? You'll likely have to (in the end) finally replace the backplane and contact your software vendors.

Like I said earlier, if this is a fun project then... Have fun... I understand. If you need a working system ASAP, I would proceed on both fronts. Get a replacement backplane for the immediate, while working on the old backplane to satisfy any unmet needs. It doesn't really sound like you are in a mission critical situation if you have time to experiment on this.

Whatever the case, good luck and happy hunting... :)
 
Last edited:
  • Like
Reactions: bsbeamer
The only software I've ever encountered that is that heavily locked down is either Windows-based, or ProTools plugins that cannot be iLok loaded (or are on an older/legacy version of iLok that likely can be upgraded to V3 for a fairly minimal cost), or legacy high-end Avid systems (before everything basically went Media Composer), or Autodesk software.

Nearly every vendor with that kind of lockdown has some sort of support that you can call (even if there is a fee involved) where you can reactivate with replaced hardware. Some would require that authorization call even with a minimal system change of HDD > SSD via clone. They do understand hardware fails and if you paid for your software, they are almost always very helpful.

If your software is pirated, you're out of luck. If the manufacturer is bankrupt with no one taking over their assets, etc. that is a much different tougher situation. Rarely does the consumer sector run into issues like that. It's usually large corporate or government-style setups with RSA keys.
 
Cineform first light. It is now discontinued and i have all my stereo 3d edits in that format. My capacitance meter should arrive tomorrow
 
zcream said:
I was running a GTX 1080 ti using 6pin to 8pin cable. My psu blew. That got fixed and now there is random shutdown. I swapped cpu board with another working Mac pro. Now problem is isolated to backplane board.
I am going to replace capacitors to see if problem gets fixed. There are a total of 11 caps.
4x with 024 svpe 150 16 written.
4x with 04 680 16k
These 8 are mounted on some sort of plastic tab and surface mount solder.
There are 3 others. 2x with 022 svpe 100 16 and 1x with 027 svpe 100 16 and I think these three are next to some sort of regulator.
ac9a236b93e4e2a8d208506878a9167a.jpg
cae272b82b0c042488fbbca3ffb37037.jpg
dcf4252d9053e833219f8d667c36cb6f.jpg
68d4ac39e5d464b615ef4176aab58b12.jpg
99fd85353fb73407dc2c9213cb4c7efe.jpg
Click to expand...
This board is very corroded, look the clock generator. You won't repair it reliably anymore.

You can always remove the BootROM and Ethernet SPIs and install on a replacement backplane, this way you will have the same hardware IDs and MAC Addresses.
 
tsialex said:
This board is very corroded, look the clock generator. You won't repair it reliably anymore.

You can always remove the BootROM and Ethernet SPIs and install on a replacement backplane, this way you will have the same hardware IDs and MAC Addresses.
Click to expand...
@tsialex it's mainly small specs of dust.
 
This is one of the 100/16 ones I had in mind for maybe causing the smear. Must measure ESR on my spare board...

zcream, have you measured or just swapped ?
 
I just swapped. If you take it out, please let me know how you desoldered. I think it's the lead free solder. My solder sucker, wick nothing worked.
I had to rip out the old cap.
I got lucky with this project.
 
I measure it built in. Thats the benefit of an esr meter. i will desolder it to investigate. Sometimes it is hard. Adding leaded solder and flux sometimes helps, a little preheating from the other side also.

Thats modern technology. When I do ancient electronics where components just fall out when showing them the solder tip :) I wish it is every time just that easy...
 
Is the mesr-100 esr tester a decent one? I ordered it. The Mac Pro is not starting up now.
Maybe I lucked out last time.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back