I replaced the screen on the laptop but the screen was fully white. I reattached the old one and it was working fine but that one is cracked. When i reattached the new one again and tried to start the laptop the fan and the lights started but few sec later the laptop is shuting down. I tried without battery or with another ram but same thing again. Any suggestions?
Did you make sure that the replacement is the exact same one that you are removing? If it isn't, that is probably the issue right there. However, if it is the right one, and is exactly the same, then there is probably a flaw in the new display.
Did you try pulling the CMOS battery and then reinserting it to see if that resolved it? It doesn't sound like that to me, but can't hurt. It really does sound like something got shorted. The display should be connected to the motherboard via a cable, so if there was a problem with the display it could have caused a problem that way. Should of testing everything though, I can't say from here what component would be the issue.
If you feel comfortable testing it all yourself, then that is what I would do. However, if not, I would try a local tech.