After looking again, I think I may have jumped to the wrong conclusion. While the issue occurs after AC power has been removed, it appears to be related to when the monitor is no longer in standby mode. Is it normal for the motherboard to to post error beeps when there is no VGA connection...
OK, so after a little more testing I've discovered that the problem only occurs after power has been removed from the PC. ie, after shut-down, when the mains power is switched off at the socket. The first boot up after power on will trigger the beeps, but subsequent boot ups will be normal...
Mmmm. Why would this only happen when the PC is booting up and initialising the BIOS? As soon as windows loads, the display comes back on! Would updating the drivers for the GPU make any difference?
I received my new PCS desktop on Saturday, but I'm experiencing problems with the display output.
Occasionally during boot up, the motherboard will sound a long beep followed by three short beeps and then the monitor will show 'no signal'. Every time this happens, the display is restored once...