If the computer is working and the problem is that there is no display then the problem could well be with the DVI to VGA adapter. Many of these adapters are not compatible with certain monitors, to test this connect the monitor to the computer with the power off to the computer. If you get the message "cable disconnected" then you have this problem. Not all DVI to VGA adapters are wired the same, the ones that come with the graphics card are normally OK and the cheap ones you get from eBay, Poundland etc are missing some of the wires that some monitors require. This is a big problem and I have encountered it many times. I keep a fully wired adapter for testing purposes so I don't get fooled by this problem.