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MP 1,1-5,1 Mac Pro 5,1 no video output
- Thread starter monoturbo
- Start date
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Hi tsialex!
I've got a cMP 4.1 Dual CPU which has the following symptoms when I press the power button:
- Fans starts to spin
- 5V LED is orange, PSU PWR, EFI, GPU LEDs are Green ( so the SYS_PG is missing / OFF )
- No boot screen
- No Chime
What I've tried:
1 - "Safe mode"
Removed the power cord and while I'm pressing the power button a plugged in the cord again. In this case the CPUA and CPUB LED were RED.
2 - Remove RAM
NONE of the LEDs were RED on the tray
3 - Replace the CPU tray with a 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all RED
---- Removed a RAM ( only 24GB were installed ), the memory LEDs were all OFF, but the previous symptomes were still there
4 - Replace the EFI Code ( I followed your tutorial )
I've desoldered the IC, extracted the original NVRAM and serial number part.
Erased the IC, the related parts has been injected into MP51.fd and it has been programmed into the chip.
After it the symptomes are the same with the 4.1 CPU tray
5 - After the EFI modification I've tried with the 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all OFF even with 32GB or 24GB RAM.
All other symptomes are the same.
6 - Replace the GPU
All symptomes were the same.
7 - Removed all drives ( ODD/HDD/SSD )
All symptomes were the same.
Do you know what means the SYS_PG?
Is there any other option that I can try before replacing the backplane?
Thanks for your help!
I've got a cMP 4.1 Dual CPU which has the following symptoms when I press the power button:
- Fans starts to spin
- 5V LED is orange, PSU PWR, EFI, GPU LEDs are Green ( so the SYS_PG is missing / OFF )
- No boot screen
- No Chime
What I've tried:
1 - "Safe mode"
Removed the power cord and while I'm pressing the power button a plugged in the cord again. In this case the CPUA and CPUB LED were RED.
2 - Remove RAM
NONE of the LEDs were RED on the tray
3 - Replace the CPU tray with a 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all RED
---- Removed a RAM ( only 24GB were installed ), the memory LEDs were all OFF, but the previous symptomes were still there
4 - Replace the EFI Code ( I followed your tutorial )
I've desoldered the IC, extracted the original NVRAM and serial number part.
Erased the IC, the related parts has been injected into MP51.fd and it has been programmed into the chip.
After it the symptomes are the same with the 4.1 CPU tray
5 - After the EFI modification I've tried with the 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all OFF even with 32GB or 24GB RAM.
All other symptomes are the same.
6 - Replace the GPU
All symptomes were the same.
7 - Removed all drives ( ODD/HDD/SSD )
All symptomes were the same.
Do you know what means the SYS_PG?
Is there any other option that I can try before replacing the backplane?
Thanks for your help!
SYS_PG is the Power Good signal from the PSU, usually when it's off is a defective PSU. Test your PSU with another Mac Pro.Hi tsialex!
I've got a cMP 4.1 Dual CPU which has the following symptoms when I press the power button:
- Fans starts to spin
- 5V LED is orange, PSU PWR, EFI, GPU LEDs are Green ( so the SYS_PG is missing / OFF )
- No boot screen
- No Chime
What I've tried:
1 - "Safe mode"
Removed the power cord and while I'm pressing the power button a plugged in the cord again. In this case the CPUA and CPUB LED were RED.
2 - Remove RAM
NONE of the LEDs were RED on the tray
3 - Replace the CPU tray with a 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all RED
---- Removed a RAM ( only 24GB were installed ), the memory LEDs were all OFF, but the previous symptomes were still there
4 - Replace the EFI Code ( I followed your tutorial )
I've desoldered the IC, extracted the original NVRAM and serial number part.
Erased the IC, the related parts has been injected into MP51.fd and it has been programmed into the chip.
After it the symptomes are the same with the 4.1 CPU tray
5 - After the EFI modification I've tried with the 5.1 single CPU tray with 32GB RAM
Fans are start to spin with full blast.
Memory LEDs were all OFF even with 32GB or 24GB RAM.
All other symptomes are the same.
6 - Replace the GPU
All symptomes were the same.
7 - Removed all drives ( ODD/HDD/SSD )
All symptomes were the same.
Do you know what means the SYS_PG?
Is there any other option that I can try before replacing the backplane?
Thanks for your help!
It's getting more interesting but in the wrong way
I removed the plastic shield from the backplate's PSU connector soldering, so I could measure the voltage after I turned it on.
The measured voltages were the desired one, so It seems that problem is with the backplane or with the communication between the PSU and the backplane.
Do you have some advice to detect the exact issue without donor backplane or psu?
Without access the LITTLE_FRANK interface or the schematics to know the test points values, is extremely difficult to diagnose a defective Mac Pro. Borrow/buy a Mac Pro (early-2009 to mid-2012 works for diagnostics) and test each part one by one.