What is causing my screen to not turn off after the established time? Screen is set to turn of in 2 minutes. But this does not happen.
How to find the cause?
If relevant I have a Samsung Galaxy Tab P7500 running Android 3.2.

UPDATE
To clarify questions from the comments:

Device is not connected
I have numerous apps installed, so I can't check who is holding the screen by uninstalling it one by one. I want to find the possible malware by some tool or programmatically.
You can use Wakelock Detector to find out what app is causing the behaviour. Remember to read the correct procedure from the app's info:


  How to use:
  
  1 Install the app 
  
  2 Charge your phone above 90% and unplug cable (or just reboot the phone)
  
  3 Give it a time (1-2 hours) to accumulate some wakelock usage statistics
  
  4 Run “Wakelock Detector”, it will display wakelock statistics for you!
  
  5 Check the apps on the top, if they show very long wakelock usage time then you found the cause of your battery drain!
  
  *Note: Wakelock Statistics are gathered since Step#3