help req'd v7 with messiah

[FTM]

fitted messiah pro to v7 ps2, no bridged solder joints, no crossed / nipped wires, everything spot on (fitted over 20 chips without problems) turns m/c on, black screen,no blue light for tray eject (will not eject), no disc activity? removed chip & wireing, still n.g. anyone had this problem? searched on google & found similar faults, seen something about ba chip or fuse??
cheers

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