I'm assuming its connected correctly (via a 6pin PCIe cable and an 8pin via MOLEX adapter from PSU cables), as surely it wouldn't even show the BIOS if the power was incorrectly connected.
I'd rather not set the BIOS to use the PCIexpress card only and ignore the embedded GPU, in case something goes wrong and I lose all video, but I'll see what other settings there are in the BIOS.
I'll check for BIOS updates.
I'm fairly sure it isn't a set up issue, as it has been allowed to run for some time on a blank screen. The HDD operates for a while then goes quiet (as in usual start up).
Unfortunately I do not have access to another PC to check it.