Bush LT26MICA has no picture or sound - what's the likely cause?

Bush LT26MICA TV stopped working today. It still powers up as the power LED is working. The remote works as I can switch it from stand by to on, but there is no sound or picture (black screen). None of the other remote or TV buttons have any affect. The menu indicators do not show either. I have tried switching the source but this doesn't work.

How do I start to troubleshoot this problem?
What is the most likely cause, a simple fuse or a board that has gone?