I just bought a used Dell UltraSharp 3007WFPT. It didn't come with a power cable or DVI cable. I know it needs a dual-link DVI cable to perform at the highest resolutions. I have a question about the power cable though. I pulled the power cable from my HP 20" monitor and plugged it into this monitor. It started up fine and then changed from color to color for the entire screen. Would it be all right to use this power cable or do I need a certain wattage to ensure the monitor's safety? Thanks.