I have an ibm thinpad t40, i had got it from someone else, it had been sold to me. one day the screen just went out. BUT, recently iv'e opened it and looked at it, cleaned it and the screen came back on, it was working. thn it just went out and I can't get the screen on. I have no idea how the screen came back on but it happened after i opened it. Any ideas on how to fix this?