Duo 2 se problem

[emerald1]

Hi had a duo2 se installed yesterday. My mate an electonics engineer installed it and checked it twice. When he turns it on the fan and disk spin, the television selects the correct AV channel however it stays there with a black screen. He has since de-soldered the chip leaving the 17 wires taped up and the ps2 is working again. Do you think its a dud chip or is something not been done correctly (a boot sequence maybe). What normally happens if a modchip fails. Bought the chip from www.xraychips.com and it a v5 or v6 ps2. Appreciate all help and thanks in advance.