Hope someone can shed some light on this problem......
While trying to install a second HDD (sucessfully, at first!), when I came to restart the PC I got a blank screen, with no sign of the hard drive(s) booting up.
I sourced an alternate motherboard (same make - P4 4 socket 478) and swapped he old one out, but still nothing. The HDD's don't appear to be doing anything when I power on. I've got power to the motherboard OK (fans working) and I've removed/replaced all the connectors to make sure they were all OK. Still nothing. The monitor doesn't show any activity and the HDD activity light on the front of the PC is staying unlit.
PC is a HP Pavillon T340, P4.