Please don’t contact support without trying a few things first. As @anon9505190 sais support is swamped and it takes them a long time to reply, so it helps no one if they reply to your request weeks from now when your issue was long solved by the forum. If we can’t solve it that contacting support is the logical next step, but please give us a chance first.
@anon9505190 you can suggest support to investigate downtime when they have the time for it, but telling everybody whose issues can presumably be solved by the forum to contact support only increases the backlog and therefore your precious downtimes.
@sadie When you say “blank screen” I assume you are talking about a black screen or do you still see something on the screen (like e.g. the status bar)?
What lidwien suggests is called a battery reset, that’s a good idea. While you got your battery out you could also try to remove the screen and clean it carefully. If you have troubles removing the screen there are some tips here. If could be your screen simply lost connection to the phone.
We have a few topics about #blackscreen. You could also check if you find a solution in one of them.