I replaced the system board on my IBM thinkpad 600E because the original problem was that everytime the system booted up it would keep going to the time (time would not stay). I know that there is a battery on the system board but I figured it would be less of a hassle if I just replace the system board. I did that and now the system will not boot up. The LED's come on and I hear the fan run but nothing will show up on the screen. What should I do?