Replaced motherboard. No display.

The power jack broke off, so I replaced the motherboard. Now the battery charges, the cd tray ejects, lights go on and the fan runs for a bit after turning it on. I tried a LCD monitor, but I got nothing on that either. I see a CRT/LCD key and hitting that with the Fn key doesn't change anything. What can I do next? Is there a way to test each component? Or is there an obvious culprit here?