MP 1,1-5,1 CPU B failure - Mac Pro 1,1 2,1.

[StickoMC]

So, I have swapped out Logic Board, Ram, Ram Trays, CPUs, CMOS Batteries, Drives, quite literally everything in this Mac Pro, and it still doesn’t work.

On both the motherboards, with two different sets of Xeon CPUs it says that there is a problem with CPU B with the red light on the Logic Board. How?

The system started to go haywire once I swapped the drives in it, and slowly degraded after a week in to a state of basically none functional. It booted to a black screen and a blinking cursor on the top left.

I tried everything and the system only came up with a CPU error once I changed the CMOS battery, what do I do from here? Should I replace the power supply? Buy new CPUs or buy a new Logic Board?

The original Logic board was flashed to 2,1, and I have been told by the seller of the new Logic board that it also has been flashed. The only symptoms of life that I got, where when I used the old CPUs on the new Logic board. It chimed, went to a white screen, and showed a CPU failure on CPU B once again.

It’s a Mac Pro 1,1 / 2,1 from 2006.
Thank you, hope someone can help or find this at least interesting.

Sincerely,
Mark.

 

[Nguyen Duc Hieu]

So, I have swapped out Logic Board, Ram, Ram Trays, CPUs, CMOS Batteries, Drives, quite literally everything in this Mac Pro, and it still doesn’t work.

On both the motherboards, with two different sets of Xeon CPUs it says that there is a problem with CPU B with the red light on the Logic Board. How?

The system started to go haywire once I swapped the drives in it, and slowly degraded after a week in to a state of basically none functional. It booted to a black screen and a blinking cursor on the top left.

I tried everything and the system only came up with a CPU error once I changed the CMOS battery, what do I do from here? Should I replace the power supply? Buy new CPUs or buy a new Logic Board?

The original Logic board was flashed to 2,1, and I have been told by the seller of the new Logic board that it also has been flashed. The only symptoms of life that I got, where when I used the old CPUs on the new Logic board. It chimed, went to a white screen, and showed a CPU failure on CPU B once again.

It’s a Mac Pro 1,1 / 2,1 from 2006.
Thank you, hope someone can help or find this at least interesting.

Sincerely,
Mark.

I got this issue once. MP1,1, original GPU nVIDIA GT7300.

Reason:
It turns out that the NPRAM search for a Windows partition to boot, and when it couldn't find one, it will display a blinking cursor on the top left of a black screen.

How to fix: Clear (reset) NPRAM by pressing and holding Command+Option+P+R at powerup until hearing 3 chimes. (Back then the MP was my first Mac computer, I had to take it to a repair shop to have OS X Lion re-installed. While the Mac was at the store, I read about NPRAM resetting trick)

It won't fix the dead CPU, though. Just OS issue.

 

[vrodion]

Today after CMOS battery replacement my Mac Pro have the same problems. Swapped CPUs but problem still present

 

[vrodion]

GPU was defective in my case

 

[StickoMC]

GPU was defective in my case

Ok, that is very interesting! Will by a new GPU anyways. Will research how to flash one. Any recommendations? I was personally thinking an NVidea Quadro for my specific needs..

 

[StickoMC]

Today after CMOS battery replacement my Mac Pro have the same problems. Swapped CPUs but problem still present

So, does that mean the CMOS battery has something to do with it? I tested mine with a Volt Meter and it still shows around 2.8V.. should be fine right?

 

[StickoMC]

I got this issue once. MP1,1, original GPU nVIDIA GT7300.

Reason:
It turns out that the NPRAM search for a Windows partition to boot, and when it couldn't find one, it will display a blinking cursor on the top left of a black screen.

How to fix: Clear (reset) NPRAM by pressing and holding Command+Option+P+R at powerup until hearing 3 chimes. (Back then the MP was my first Mac computer, I had to take it to a repair shop to have OS X Lion re-installed. While the Mac was at the store, I read about NPRAM resetting trick)

It won't fix the dead CPU, though. Just OS issue.

Very interesting, I was messing around Dwight windows on my system, however it no longer registers any keyboard commands on boot, as it doesn’t even start up to an Apple logo anymore.. will definitely try that as a follow up once CPU issue is fixed.

 

[Macschrauber]

So, does that mean the CMOS battery has something to do with it? I tested mine with a Volt Meter and it still shows around 2.8V.. should be fine right?

No, below 3.0v is dead. This type holds around 3,2v until it drops suddenly

It is not a cmos battery, this is for the clock processor, it is important for energy management and system timers.

 

[StickoMC]

Ok. That is interesting!! What battery replacement should I get then? A C2032B?

 

[Macschrauber]

the correct type is BR2032C, this is hard to get but the type what stands the high temperatures.

For test sake you can use a normal 2032C you will find in your drawer (if is is over 3,0 volts). But that type will not last long in a Mac Pro.

 

[StickoMC]

the correct type is BR2032C, this is hard to get but the type what stands the high temperatures.

For test sake you can use a normal 2032C you will find in your drawer (if is is over 3,0 volts). But that type will not last long in a Mac Pro.

Okay, where would I find those batteries?

 

[Macschrauber]

As I am in Europe I cant help. I would take a CR2032B first, one of the most used coin batteries.

If that is the cure you will hunt for the high temperature one.

 

[Macsonic]

Okay, where would I find those batteries?

For CR2032, you can try Amazon and check. Watch repair shops or electronic stores are other options. Macschrauber is correct, that BR2032C is the better choice but harder to find.

CR2032

Amazon.com: CR2032B Battery

Amazon.com: CR2032B battery

www.amazon.com

 

[StickoMC]

Ok, i have some good news! I changed the CMOS battery and the system seems to have booted, however I have no video output and I already tried a PRAM reset… apart from buying a new GPU, any suggestions?
I also tried the buttons on the motherboard to no avail.
It has drive activity and all status indicators say everything is fine. It even accepts Keyboard Presses on boot.

 

[flat4]

For CR2032, you can try Amazon and check. Watch repair shops or electronic stores are other options. Macschrauber is correct, that BR2032C is the better choice but harder to find.

CR2032

Amazon.com: CR2032B Battery

Amazon.com: CR2032B battery

www.amazon.com

no kidding, i bought the wrong ones because most sellers try to dupe you.

From amazon

 

[StickoMC]

no kidding, i bought the wrong ones because most sellers try to dupe you.

From amazon

Ohhh! Well. That is good to know! I just found a spare laying around! It came from a Server so I have no doubts that it will at least work for now.

 

[StickoMC]

So I was looking at GPU compatibility lists for Mac Pro 1,1 and 2,1s but they are extremely limited. Is that only on MacOS by chance or is that hardware capability? Because I’d like to use the system for ProxMox. (Does Linux have a better GPU list for this system?)

 

[StickoMC]

Turns out, I was so excited of the idea that it booted, that I forgot to turn the monitor on…
Nothing to say apart from “whoops”.
But I have video now! So that’s great!! Got the system fully up and running!

 

[StickoMC]

Thank you all for your patience and help with my weird project! You guys have no idea how much I appreciate you all for this! Without you, this would not be possible.
Here I am hoping that this forum will one day help someone else with their project 😊

 

[Macschrauber]

again: Thats no cmos battery. This box its NVRAM is stored inside a flash chip.

the battery is for the RTC (Real time clock - clock / timer processor)

 

[Nguyen Duc Hieu]

Thank you all for your patience and help with my weird project! You guys have no idea how much I appreciate you all for this! Without you, this would not be possible.
Here I am hoping that this forum will one day help someone else with their project 😊

So in the end, what did you think solved your problem?
NPRAM reset?
CMOS battery replacement?

 

[Madr]

I got this issue once. MP1,1, original GPU nVIDIA GT7300.

Reason:
It turns out that the NPRAM search for a Windows partition to boot, and when it couldn't find one, it will display a blinking cursor on the top left of a black screen.

How to fix: Clear (reset) NPRAM by pressing and holding Command+Option+P+R at powerup until hearing 3 chimes. (Back then the MP was my first Mac computer, I had to take it to a repair shop to have OS X Lion re-installed. While the Mac was at the store, I read about NPRAM resetting trick)

It won't fix the dead CPU, though. Just OS issue.

Thanks for that MPRAM reset. Don't think i tried windows on this so no idea how i got the blinking cursor but your tip worked!