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mac pro 3,1 no singnal to monitor.

A

alaska man

macrumors newbie
Original poster
Feb 17, 2013
16
0
I received a 2008 mac pro 3,1 in pieces from a friend . He said that he was having trouble with the graphics cards cutting in and out and and then the power supply (PS) failed. I got a used power supply on ebay and put it all back together. I turns on, the graphic card ati 3870 (GC) fan powers up but i get no signal to the monitor. I tried all my monitors and nothing.

I tried several different OS (10.6 , 10.7 and 10.11 ) versions, I moved the GC to all the different PCI slots, i pulled the GC from my 2006, (an ati 5770), which i know is compatible and still the same results. It boots up, 'With LION OS 10.7 I booted in safe mode and blindly typed in fsck -fy command and waited, then typed reboot and it rebooted. It will boot to target mode and i can access the drive in disk utility and verify it. I have done pram, and smc resets, I tried the old PS and it fired up as well, I then did all of the above with the old power supply back in it.

I have been reading forums and post for days and can not find any more info other than it is possible it is logic board? Ideas or advice would be appreciated.
 
Last edited:
Have you connected the extra power supply cable to your 5770?
I guess that when you have tried the 5770 you have completely removed the 3870.
Any other pcie cards installed?
Are all other components, HDs, dvd-rom, etc having power?
Remove all hard disks and try to boot from an OS X dvd, just in case that there is something wrong with the hd/os...
 
filmak said:
Have you connected the extra power supply cable to your 5770?
I guess that when you have tried the 5770 you have completely removed the 3870.
Any other pcie cards installed?
Are all other components, HDs, dvd-rom, etc having power?
Remove all hard disks and try to boot from an OS X dvd, just in case that there is something wrong with the hd/os...
Click to expand...
Yes i have connected the power cable for both card i tried, nothing else in the other pci slots. it has an optical drive and i tried it with it installed and without. There is power coming off the logic board for a HD to be installed in the optical bay but nothing connected to it. I only tried booting with a HD in one of the HD slots and no others installed. I will try to boot with disc, i only have one, leopard i believe.
 
I found my install discs and booted from both. i think it booted, as there is still no signal to the monitor, Drive spins up and i can hear it read the disc.

What are other reasons can there be for a graphic card to not send a signal but still power up ( I.E. fans on ) Assuming the graphic cards i have tried are functioning properly in other machines?
 
Last edited:
alaska man said:
I found my install discs and booted from both. i think it booted, as there is still no signal to the monitor, Drive spins up and i can hear it read the disc.

What are other reasons can there be for a graphic card to not send a signal but still power up ( I.E. fans on ) Assuming the graphic cards i have tried are functioning properly in other machines?
Click to expand...

PCIe bus is damaged, and only gives power - nothing else?

Have you tried a different monitor cable?
 
If you have another Mac available, I would suggest to use this faulty mac in target disk mode, use it as a start up disk for your other mac via firewire, and setup ethernet network, then enable screen sharing. shut them down, start up both of them and check with your other mac the system profiler of the faulty one, are there any GPUs listed ? other PCIe cards, you can do a remote troubleshooting this way. At least I hope so...:) Good luck!
 
filmak said:
If you have another Mac available, I would suggest to use this faulty mac in target disk mode, use it as a start up disk for your other mac via firewire, and setup ethernet network, then enable screen sharing. shut them down, start up both of them and check with your other mac the system profiler of the faulty one, are there any GPUs listed ? other PCIe cards, you can do a remote troubleshooting this way. At least I hope so...:) Good luck!
Click to expand...
ok thanks for that. I was able to screen share, the graphics card is not listed in the system profiler. I did a software update and it did update something but still no changes. I also ordered the power cable ps3 so i will report back once i have installed that.
 
filmak said:
If you have another Mac available, I would suggest to use this faulty mac in target disk mode, use it as a start up disk for your other mac via firewire, and setup ethernet network, then enable screen sharing. shut them down, start up both of them and check with your other mac the system profiler of the faulty one, are there any GPUs listed ? other PCIe cards, you can do a remote troubleshooting this way. At least I hope so...:) Good luck!
Click to expand...
ok thanks for that. I was able to screen share, the graphics card is not listed in the system profiler. I did a software update and it did update something but still no changes.
 
Which brand of HD 5770 ? Have you tried both DVI ports ? Don't forget to change your monitor settings to match your cable setup.

What inputs does the monitor have ? DVI ? VGA ? HDMI? mDP ? DP ?

Might be worth trying a DP-DVI /DP HDMI adaptor .. . or a DVI to VGA adaptor.

Hope this helps
 
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