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mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
I have purchased a mac pro 3,1 advertised as spares/repair as it chimes but no video, so I assumed it just needed a new GPU.
I have tried 3 different GPU's but I still get no video. The RAM is working fine and the only DIAG LEDs that light up are the 2 power ones. So no EFI and no GPU.

What could be wrong?
 

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
I tried the GPU that came with it (ATI 2600XT) which could obviously be faulty, i've also tried 2x known working 8800's but get nothing. I've tried with and without a hard disk attached but always get same result - no video.
 

bookemdano

macrumors 68000
Jul 29, 2011
1,514
846
Are the cards you're using meant for the Mac Pro (i.e. have EFI firmware)? If not then you won't get a boot screen. Do you have a known-working HDD with OS X El Capitan or earlier installed?

You might try another slot in case there's something physically wrong with slot 1.
 

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
Here is a link to various MacPro Technician repair manuals. They will give detailed troubleshooting steps.

http://tim.id.au/laptops/apple/macpro/

Have already checked the service manual which doesn't really give much info about the EFI and GPU LEDs not lighting up. I suspect a northbridge problem.
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Are the cards you're using meant for the Mac Pro (i.e. have EFI firmware)? If not then you won't get a boot screen. Do you have a known-working HDD with OS X El Capitan or earlier installed?

You might try another slot in case there's something physically wrong with slot 1.

Have tried all slots. All cards i've tried are mac cards, only the nvidia cards are known working.
 

yuzgen

macrumors member
Jul 26, 2018
87
19
If that 2600XT is faulty and if there is no OS installed on the disk, it's normal not to get a video signal with PC cards. If you have another Mac, take its disk and hook it up in 3,1. You will most likely get video after MacOS finishes loading.

I tried the GPU that came with it (ATI 2600XT) which could obviously be faulty, i've also tried 2x known working 8800's but get nothing. I've tried with and without a hard disk attached but always get same result - no video.
 

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
If that 2600XT is faulty and if there is no OS installed on the disk, it's normal not to get a video signal with PC cards. If you have another Mac, take its disk and hook it up in 3,1. You will most likely get video after MacOS finishes loading.

The 8800's I tried are genuine mac cards
 

bookemdano

macrumors 68000
Jul 29, 2011
1,514
846
Hopefully someone with experience with the older cMPs can chime in, but maybe there were different versions of the 8800 GT and only certain ones are compatible with the 3,1. Really not sure, just found that page via a google search.
 

Traace

macrumors regular
Jul 21, 2018
153
137
Germany
MP 3,1 needs a card with EFI 64-Bit.
Older like MP 2,1 and 1,1 needs a card with EFI 32-Bit.
They are not compatible

I'm a ATI Boy, 6870/6850 works for 3,1 and newer. No clue about Nvidia, but my guess is your cards still have EFI 32-Bit because its are older, therefore no bootscreen on a MP 3,1.
 
Last edited:

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
Thanks for the info guys.

I also have a working mac pro 1,1. Can I install the boot drive from the 1,1 into the 3,1, with a PC GPU? This is the only thing I can think of without buying a 64 bit card.
 

bookemdano

macrumors 68000
Jul 29, 2011
1,514
846
I think the key is what version of OS X is running on the 1,1? If it is still on Tiger then it won't work in the 3,1 (minimum version of OS X for the 3,1 is Leopard). As long as you are running Leopard, Snow Leopard or Lion on the 1,1 then its HDD should boot in the 3,1.

Edit: And what PC GPU are you talking about? You would need to make sure that whatever version of OS X is on the 1,1 has built-in drivers for it.
 

Traace

macrumors regular
Jul 21, 2018
153
137
Germany
If you have a working 1,1 and a OS backup that supports your PC card then you can restore that dmg file to your 3,1 hdd (make sure its GPT). Then put the hdd back into your 3,1 together with a PC GPU. Cross fingers , wait minutes and hopefully get OS Screen :)
 

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
Well this is a bit embarrassing.....
Those 8800's were actually 7300's!! Got mixed up as i'm using one of those in another machine.

Anyway, i've got a working 2600XT which won't work in the 3,1. After the chime, the monitor switches on but no white screen. It just cycles through the inputs, says "no input" then goes into standby then instantly comes back on again and repeats. BTW this happens in all pci slots which further convinces me it's the northbridge. Is there anything else I can try before it goes in the bin?
 

yuzgen

macrumors member
Jul 26, 2018
87
19
I would try RAMs first. Only two DIMMs in the right sockets. Then take heatsinks out and check CPUs and sockets. Then if all fails, make it a Hackintosh PC, instead of throwing it away.
 

mikeyb5753

macrumors newbie
Original poster
Jun 13, 2016
13
4
UK
After trying everything, i've decided to give up. Will just advertise the board as faulty and the rest as working. If anyone's from UK needing 3,1 parts let me know.... will sell them cheap as just want rid asap.
 
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