you probably need to remove the PS2 kext from all locations it might be like S/L/E, E/E, Clover or Extra folder if using chameleon boot loader and also including prelinked kernel and caches hopefully that will get the machine to boot. obviously you will need a usb keyboard and mouse. once you get it to boot then add in the correct ps2 kext. if you are using clover then after following the above you can put the ps2 kext into clover other.