Blank Page

i have just shifted my wordpress from one server to the other. when i accessed the page initially, it opened a blank page. i disabled all plugins and the page started opening.

the problem now is that blank page is appearing on site.com/wp-admin. when i access site.com/wp-login.php, login form appears, and when logged in, it doesnt redirect and blank pag comes up again. blank page appears on accessing site.com/wp-admin/plugins.php or any file that is actually there in wp-admin directory.

Any one, any idea , pleasesesesee ????