Help! Problems with W/C 5870s

[drlawyer]

I'm hoping someone can offer some input on this ongoing issue I've been having. I have been putting together my first water-cooled system (Worklog here) including a CrossfireX setup utilizing two Radeon HD 5870 video cards. The cards are identical - both are Eyefinity 6, 2 GB cards and they display the same equipment ID tag (on the rare occasions I can get both to work).

So, here's the problem - I installed Danger Den DD-Summit water blocks on two cards. The primary card works flawlessly. However, I have had ongoing issues with the second card, which I have now replaced twice. At present, this third card is not working.

The symptoms varied, somewhat. The first time around, I think I damaged the video card by applying thermal paste directly to the memory chips (which is what DD recommends, but it just doesn't feel right). I tested the second card in its OEM form and had no issues, but once I installed the water block, it never worked right. Same with the third.

The current symptoms are: when both cards are installed and active, Windows will freeze up at the same point in the login (Windows 7, when the logo appears, right before the User screen pops up). This led me to believe it was a driver issue, but I've run through all the mechanisms I can find involving removal / reinstallation of drivers, repairing installations, restoring to earlier drivers and even, finally, conducting a format and clean reinstallation of the entire OS. I've tried the last three Catalyst driver series, and have attempted to install only the drivers without all the bloatware. The system will boot to Safe Mode with both cards active, and will recognize both cards. However, when I tried to install drivers in safe mode, I encountered the "Driver detection not found" error, and couldn't complete a full Catalyst Suite install in safe mode.

I have confirmed that power is not the issue - I upgrade my PSU to a Corsair AX1200, which is what both AMD and Corsair recommend for this rig. When I disable the auxilliary video card, everything runs smoothly.

(deep breath)

Okay, I know that is scattered, and I know you will need more and probably specific information to assist, so ask away. Any help troubleshooting this would be greatly appreciated.

 

[drlawyer]

I have tried disabling the primary card and running just the second card. The system does not produce a video signal. I'm thinking hardware (obviously) but it seems odd that three video cards in a row all were defective.

 

[drlawyer]

Quick update on this situation, for those who are experiencing similar issues. I think I have discovered what the problem has been (or at least, part of the problem).

There was a chip on the surface of the card that was high enough to make contact with the water block that was not addressed in the installation instructions provided by Danger Den. Once I insulated the area with a layer of thermal tape, the system now boots into Windows without incident (now I'm just working on getting the system to properly configure the card, which I am concerned may have been damaged by the prior contact between the chip and the block).

I will take some pictures of the area I'm talking about on the card and post them later for reference, as I realize that the explanation above is a little vague.

As I said, I'm now working on getting the system to properly configure the second card, and will update with further details once I make some additional progress.