This is a strange problem.
A customer brought in a Dell Mini 1012 to replace the screen since it was cracked. I'm not sure if it was a fall or stepped on. I replaced the screen and it was working fine. When the customer picked it up, I showed him it was working. When I had my head turned from the unit, the screen went black on it. Now no video comes up on it at all.
The video cable was connected correctly on both ends. I even replugged both ends to make sure. I ordered a replacement video cable sensing that was the problem. Same result - black screen. External video works fine so it is working and booting to Windows XP.
Even the bad cracked screen doesn't have video either which it did prior to the blackness issue.
With the battery and power adapter not connected, I held down the power button for close to a minute. It didn't help. Reseated memory. Hard drive isn't connected. I connected the other end of the video cable for the web cam but didn't think it was required to get video on screen.
I'm thinking something happened on the motherboard related to the screen being cracked on the unit.
Mark