When I turn on the computer the monitor says, check power signal and shuts off. What can I do. I have switched monitors and have switched the power cords. It is Windows xp. Also the computer does not shut off with the power button on the front. I have to unplug it. 

                         PCBUILD's List Owners:
                      Bob Wright<[log in to unmask]>
                        Mark Rode<[log in to unmask]>