Hi, I'm new, this is my first post. I replaced the motherboard on my 4600, but can't get past the Dell startup screen. It just goes to a blank screen with a blinking cursor in the upper left corner. Putting an XP install disc in the drive doesn't do anything. Setup sees my HDD. I've removed all but one stick of RAM. I've tried changing the battery and PSU. The diagnostic codes on the board are all green like they're supposed to be. I'm out of ideas, can anyone help? Thank you.