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Mac Pro 4,1 - Fried Logic Board?

R

rowanstar

macrumors newbie
Original poster
Jun 22, 2018
3
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I've searched on here and can't find my exact issue.

Was installing a new GPU, the GTX 780TI. That worked but then I decided to see if I could get the original GPU installed as well in another PCIe slot. Saw somewhere that someone had used power from two of the SATA ports used for the hard drives to power their second GPU. Thought it was worth a shot despite everywhere saying that I would def need a second power supply with the 780TI. Dumb, I know.

Powered it up and of course, everything **** the bed. Red LEDs lit up on the processor tray, the CPU fans went into overdrive but none of the other fans turned on, there was no chime and my screen remained black.

So I powered down, took out the extra GPU and tried to power up again. Same issue. I switched the 780ti out for the original GPU and powered up. Same issue. Finally I followed the Apple Technician Guide, pulled everything out and put in things one by one. Here are my results:

Step 3: 5V STBY LED illuminates
Step 5(add processor tray): 5V STBY LED illuminates
Step 7(power on with processor tray): On Power up PSU PWROK (green), 5V STBY (amber), EFI DONE (Flashes green then goes dark), GPU OK (flashes green then goes dark) LEDs illuminated
Step 10: 5V STBY LED illuminates
Step 11: The red-colored error LED on the processor board flashed once only as the Mac Pro powers on. Startup tone heard. Front and rear processor cage fans spin slowly
Step 13 (install the hard drive): Red LED on processor board illuminates, CPU fans go into overdrive.

Step 13, installing the hard drive, is where I stopped following the guide since it seemed I had found the culprit of the issue. I pulled out the hard drive and attempted to install another one. Same issue.

I took out the hard drive completely and installed the original GPU to test if it was a power supply issue. Started it up and I heard the startup tone and all the fans were spinning normally. Checked the DIAG button and got:

PSU PWROK(green)
5V STBY (amber)
SYS PG (green)
EFI Done (black)
GPU OK (black)
No lights on the processor board

After that I tried to install the hard drive, this time in a slot I had never used before and the whole thing **** the bed again. Red lights on the processor board, overworked CPU fans, no chime and no front or rear cage fans.

It seems to me this is a logic board issue. I'm thinking I fried the hard drive SATA ports? Or did I over tax the Power Supply and now it can only power a GPU?

Just want a second opinion before I drop the cash to buy a new logic board.
 
rowanstar said:
I've searched on here and can't find my exact issue.

Was installing a new GPU, the GTX 780TI. That worked but then I decided to see if I could get the original GPU installed as well in another PCIe slot. Saw somewhere that someone had used power from two of the SATA ports used for the hard drives to power their second GPU. Thought it was worth a shot despite everywhere saying that I would def need a second power supply with the 780TI. Dumb, I know.

Powered it up and of course, everything **** the bed. Red LEDs lit up on the processor tray, the CPU fans went into overdrive but none of the other fans turned on, there was no chime and my screen remained black.

So I powered down, took out the extra GPU and tried to power up again. Same issue. I switched the 780ti out for the original GPU and powered up. Same issue. Finally I followed the Apple Technician Guide, pulled everything out and put in things one by one. Here are my results:

Step 3: 5V STBY LED illuminates
Step 5(add processor tray): 5V STBY LED illuminates
Step 7(power on with processor tray): On Power up PSU PWROK (green), 5V STBY (amber), EFI DONE (Flashes green then goes dark), GPU OK (flashes green then goes dark) LEDs illuminated
Step 10: 5V STBY LED illuminates
Step 11: The red-colored error LED on the processor board flashed once only as the Mac Pro powers on. Startup tone heard. Front and rear processor cage fans spin slowly
Step 13 (install the hard drive): Red LED on processor board illuminates, CPU fans go into overdrive.

Step 13, installing the hard drive, is where I stopped following the guide since it seemed I had found the culprit of the issue. I pulled out the hard drive and attempted to install another one. Same issue.

I took out the hard drive completely and installed the original GPU to test if it was a power supply issue. Started it up and I heard the startup tone and all the fans were spinning normally. Checked the DIAG button and got:

PSU PWROK(green)
5V STBY (amber)
SYS PG (green)
EFI Done (black)
GPU OK (black)
No lights on the processor board

After that I tried to install the hard drive, this time in a slot I had never used before and the whole thing **** the bed again. Red lights on the processor board, overworked CPU fans, no chime and no front or rear cage fans.

It seems to me this is a logic board issue. I'm thinking I fried the hard drive SATA ports? Or did I over tax the Power Supply and now it can only power a GPU?

Just want a second opinion before I drop the cash to buy a new logic board.
Click to expand...

You kill all SATA ports? e.g. even connect the optical drive will cause the same issue?

TBH, I don't think your setup can kill the 980W PSU, far from that.

However, kill the SATA port by drawing too much power from it is totally possible.

If your cMP can present the start up tone with no HDD installed, but the issue come back once you install the HDD, then I will say it's quite obvious the SATA port cause the issue. And since it's a part of the logic board, so, yes, it seems your logic board is damaged. (I assume you remove / install all hardwares correctly during GPU installation and minimum equipment test)

Understand that EFI DONE and GPU OK LED are not normal. But since you can get the start up tone. That's means somehow "bootable". The cMP can boot headless anyway.
 
Do you have picture on monitor? If no picture, do you by any chance have a GPU that doesn't need extra power? If so, test with it.

Quick test for SATA port and HDD: Use SATA cable and power of the optical bay.
 
h9826790 said:
You kill all SATA ports? e.g. even connect the optical drive will cause the same issue?

TBH, I don't think your setup can kill the 980W PSU, far from that.

However, kill the SATA port by drawing too much power from it is totally possible.

If your cMP can present the start up tone with no HDD installed, but the issue come back once you install the HDD, then I will say it's quite obvious the SATA port cause the issue. And since it's a part of the logic board, so, yes, it seems your logic board is damaged. (I assume you remove / install all hardwares correctly during GPU installation and minimum equipment test)

Understand that EFI DONE and GPU OK LED are not normal. But since you can get the start up tone. That's means somehow "bootable". The cMP can boot headless anyway.
Click to expand...


Yeah, I didn't really think it was the power supply. I agree, it looks like the SATA port which means I've got to replace the whole logic board. You said 'EFI DONE and GPU OK LED are not normal'. Does that mean they're not normally lit up? Or is it abnormal that they're not now lit up?
[doublepost=1533658526][/doublepost]
yuzgen said:
Do you have picture on monitor? If no picture, do you by any chance have a GPU that doesn't need extra power? If so, test with it.

Quick test for SATA port and HDD: Use SATA cable and power of the optical bay.
Click to expand...

There's no picture and I've already switched to the original GPU that didn't need additional power. It's the ATI Radeon HD 4870. I've also already tested the HDD in a separate enclosure to ensure it was working.
 
rowanstar said:
Yeah, I didn't really think it was the power supply. I agree, it looks like the SATA port which means I've got to replace the whole logic board. You said 'EFI DONE and GPU OK LED are not normal'. Does that mean they're not normally lit up? Or is it abnormal that they're not now lit up?
[doublepost=1533658526][/doublepost]

There's no picture and I've already switched to the original GPU that didn't need additional power. It's the ATI Radeon HD 4870. I've also already tested the HDD in a separate enclosure to ensure it was working.
Click to expand...

You MUST connect both 6pins on the 4870, otherwise, it won't work.
 
I meant you could hook up your HDD to your optical drive's cables, but not anymore.

Since you have a 4870, you have a 1,1, I suppose. They have two IDE and power cables for optical drives.

Here in Turkey, you can buy 3 1,1s instead of a 780 Ti. It's not worth buying a mobo, if it's fried. Maybe take the opportunity to buy a 5,1? It will be happy with a 780 Ti, unlike 1,1.
 
yuzgen said:
I meant you could hook up your HDD to your optical drive's cables, but not anymore.

Since you have a 4870, you have a 1,1, I suppose. They have two IDE and power cables for optical drives.

Here in Turkey, you can buy 3 1,1s instead of a 780 Ti. It's not worth buying a mobo, if it's fried. Maybe take the opportunity to buy a 5,1? It will be happy with a 780 Ti, unlike 1,1.
Click to expand...

4870 is an options for 4,1, not 1,1.
 
h9826790 said:
4870 is an options for 4,1, not 1,1.
Click to expand...
Yeah, It's a 4,1. Also, I connected both 6 pins. The GPU works fine. I'm pretty positive now that I fried the HDD SATA. Unless anybody else has another explanation.
 
rowanstar said:
Yeah, It's a 4,1. Also, I connected both 6 pins. The GPU works fine. I'm pretty positive now that I fried the HDD SATA. Unless anybody else has another explanation.
Click to expand...

If your GPU works fine, you would see picture on your monitor. Why would fried SATA ports cause no picture on screen?

PSU looks guilty to me. I would still try low power GPU without 6 pin sockets. If younhave MacOS on your HDD, you should see youeir desktop, because mobo is working, controlling fans properly.

Hook up your HDD to optical drive bay and try a low power GPU. If you see your desktop, I suppose you need a PSU, rather than a mobo.
 
If your cMP is a dual quad . .remove CPU "B". . try booting from "CPU A" with all 4 RAM slots populated.
If that works .. please report back.
 
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