Xbox 1.4 X3 problem

[waters31]

I've installed the X3 in a v1.4. It boots up and i get the flash menu, but
after a few seconds the picture freezes and displays vertical lines. After that it reboots and frags a couple of times. I've gone over the pinheader
solder points but all looks ok. Any idea?

//waters

 

[TheMask]

mod chips?

should I invest in one? are they worth using? and can they act as a simpler to do jtag? I've got an xbox on the old blade dashboard that is jtaggable if that means anything. This is pretty much the only area I know nothing about and google searching made me really confused.
thanks in advance!