Sounds like it is the firmware as the standard firmware won't work with the newer A64 m/b chipsets which is the problem I had, you need to update the firmware but you can't do that until you have the system up and running. If the PC isn't firing up this is because it's being held in reset by the mach II and it's not triggering at the boot temp. You'll need to fool the pc into powering up when the mach ii hit's the correct temp, with the standard unit this defaults at -33, with the GT I think it's slightly lower, -36 or something but someone else can confirm. You need to go through the standard power up, keeping an eye on the mach ii display, when it hits the boot temp you need to short the two power terminals on the m/b where the blue and white connectors from the mach ii would normally connect with something metallic such as a screwdriver. Also, if you keep the connectors on until it hits the boot temp and then remove them you may find this triggers it as it does with mine without having to short the terminals. Once the PC boots you can reconnect the blue/white leads to the terminals, once you boot into windows you can upgrade the firmware to 821, there's a sticky at the top of this thread for download and install instructions. Hope it goes without saying you should make yourself entirely sober and static free before attempting this but it's not as crazy as it sounds.
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