QUOTE
The only design flaw of the x clamps is that all the pressure goes to a pinpoint under the board. If that black piece of plastic in the middle of the xclamp was expanded to at least the size of the BGA chip you would get equal pressure from the bottom to the top, this would cancel out any uneven pressure on the mobo itself to stop it from bending. The current xclamp fix's with washers and bolts, does the exact opposite of what the original xclamp and heat has caused. Instead of the edges of the mobo around the gpu bending downward away from the chip. the fix now leaves the center of the mobo with no support from below. as you tighten the bolts the heatsink bends the mobo in the opposite direction. Since the center solder balls on the gpu most likely are still intact and fine. the mobo bends the otherway causing reconnection of the outter balls. But eventually the heat cycles will start causing other solder balls to break. In any case no matter what, there are solder balls not making proper connections and there probably will never be a permanent fix. However there might be a permanent prevention fix. If you were to do this before the solder balls are overly stressed. By simply modifying the xclamps to apply the center pressure on the mobo at at least the same size as the GPU from above. That leads you to the problem of all the little resistors and capacitors in the way on the bottom of the mobo. So as someone previously stated use a semi hard material that can allow for the little parts to indent into the material. My method is similar to this and i wont bother going into details because it's so radical from other methods. I have read,alot of those threads and I don't feel like defending myself from flammers. But it accomplishes the task of this thread. Although I can't really testify how well it works on already rrod'd systems because i do it as prevention. I still have ones as far back as 06 that are still working with this method + 9v gpu fan mod. 12v mod is too loud, and even both fans at 9v was a bit loud for me and friends so we went with just the one fan modded.
I totally agree with you lugnut.
i think i have done a similar thing to you
my xbox was rrod-ing for the second time after the xclamp 'fix.' so i thought i would replace the xclamps, and mod them to apply even pressure
I used a scrap of fibreglass circuit board with some 1.5mm balsa wood underneath, cut to the size of the gpu. the resistors sink into the balsa nicely and i cut a hole for the large smd capacitor.
i removed the little black plastic thing from the x clamp and replaced it with a washer.
so basically the xclamp now pushes down on a washer which pushes down the piece of fibreglass board which is padded by the balsa which applies even pressure to the motherboard over the entire area of the gpu.
its still going strong after 4 hours of farcry 2... hopefully it will hold up indefinitely.
I think this is worth another thread. it appears to be a LOT better than xclamp replacement.
(IMG:
http://i197.photobucket.com/albums/aa189/yaywoop/realxclampfix.jpg)
This post has been edited by yaywoop: Nov 5 2008, 06:11 PM