I downgraded a Slim PS3 yesterday, Slim 25xx, Date Code 0D, Samsung Nor (QI4D).
the Downgrade went fine and the De-hashing,
The Dump was validated using your guide in addition to the info included in the PS3Wiki validation Talk Page (although nothing major to add just checking offsets and lenghts)
but when you turn the PS3 for about 30 -45) min it freeze and gives me weird color on the TV, and had to shut it off and wait till cool.
i know it is a GBU and Heating issue? or it is a hardware flue?
is Re-Fowing the GPU going to help? (Thermal paste changed during the downgrade).
One more thing: why the hell it happens to me with the 0D code PS3 Only :-)?