hi, I had XENON 3 RROD, error 0102. I fix it with x-clamp, everything ok. I did the jtag, for that I had to remove the screws and heatsinks several times, becvause I had problems with soldering.
I had jtag ok, but now I had RROD error 0102.
I think its CPU, because I touch CPU heatsink and it is cold, its like CPU doesnt work. I change again CPU thermal compund and it was drie, then I boot my xbox 360 and worked. But thhen I turn it off and turn it on again, xbox 360 logo but RROD. And now CPU heatsink is cold like before.

What can I do ?

The xclamp replacement hack DOES NOT work very well in the long term.
Basically your 0102 error indicates that there is a solder crack in the GPU (most cases).
Replacing the Xclamp with the typical hack does nothing but squeeze the joint together. The only way to fix it is to properly reflow it.

I don't sell any rrod fixed boxes w/o reflowing it first. I really don't want people returning boxes. So after I reflow, I can simply put back the original xclamps. No problems so far.