I was able to fix one of two using the xclamp method. MIND YOU, I had to do the 1 penny per ram chip fix because the board would not bend the right way.
The biggest thing I found with this fix is that it is really revealing the XBOX 360's design flaws. The motherboard warp and the GPU's seating into its socket is seriously compromized by the slightest movements.
Once you can get the xbox to boot, getting it to NOT overheat is tough. You have to adjust the screws as the XBOX 360 is on and playing a videogame. I used 2 stools to sit the xbox motherboard with everything plugged in, and adjusted the screws and listened for the fans to not run so damn fast. Once it sounded normal and silent, i left the screws the way they were and repeated the same thing with the case screws. Adding the black screws for the CPU xclamp (which i did not remove) caused the GPU to come out of its socket, and gave immediate overheating. Just using the silver screws slowly one at a time while the xbox was running allowed me to make sure i was not stressing the board.
Now everything works great after everything is put back together, the fans are running slowly and i have been able to play many games for hours.
NOW the other xbox? it cannot boot, it will not boot, I've repeated the same procedure, and i have tried to cook it for 4 minutes, while keeping the CPU nice and cool. It does not work. The towel trick was tried by my friend several times with this unit, while the other had only been done once with a towel for 10 minutes. TOWEL TRICK IS BAD, DO NOT USE IT!