mac pro 2008 will not boot with 5770 card installed

[strangesounds]

I just received a new HD5770 apple specific card from B and H and upon install the mac pro will not boot up (no response to power button). I put the old xt 2600 back in and it booted fine. I put the HD 5770 in the #2 slot and again no boot. I unplugged the power cord from the 5770 to the motherboard and it once again booted fine. I may simply have a bad card, but before I return it, does anyone have any tips for troubleshooting? I do not have any other PCI cards installed to conflict. I have read through a lot of forums about this card and the 2008 mac pro. In spite of it not being "officially supported" it seems to work for everyone else.

Mac Pro 3,1 with 8 cores 2@ 2.8 xeon quads, 22 GB RAM, it has the firm update

OS 10.6.8

thanks

 

[MacsRgr8]

Doesn't the 5770 need 2 power cables?

 

[hfg]

I have had both the Apple branded HD 5770 and the HD 5870 working (separately of course) in my 3,1 2008 8-core Mac Pro. You do need the power cable going from the motherboard to the cards, and you might check to verify that the card is fully and properly inserted into the card-slot. You might try the other motherboard cable socket too.

If all is well with the installation, you may have received a bad card. Sounds like a hard-short somewhere is preventing the power supply from starting.


-howard

The 5770 is one cable, the 5870 requires two cables.

 

[xcodeSyn]

I may simply have a bad card, but before I return it, does anyone have any tips for troubleshooting?

It sounds like it's a bad one, but you can try it in another Mac or PC with proper power connection to see if it would work. A Mac GPU still works in a PC and it's much easier to locate one to test it. Good luck.

 

[goodcow]

Doesn't the 5770 need 2 power cables?

No, the 4870 does. I have a 5770 and it's one cable.

 

[MacsRgr8]

No, the 4870 does. I have a 5770 and it's one cable.

Okay. Tnx!

 

[Macsonic]

Might be a defective 5770HD card you got. My 5770 works fine in my 2008 Mac Pro at 10.6.8 or 10.8