What do you mean by: 'starts normally upon power up' . If it is not booting that is not a normal startup. What do you mean by: 'nor appears to be recognised by the CMOS'. Wha isn't recognised by CMOS? Even a completely dead battery won't usually stop a power up sequence if the PC is plugged into the mains. Try putting an external monitor on to see if you have a problem with the integral display.
Terry
October 2006