blank white page (please help)

new to wordpress. have installed it on server at mediatemple. works fine. then upload the theme through ftp in the theme folder. It shows up and i click activate then bam!!! all i get is blank white pages. I remove theme from wordpress through ftp and then it works again. It works fine theme and all on my local mamp server but i can’t figure out how to fix on the mediatemple server? Any help would be appreciated.
Thanks.