Fix Dark-Screen TV

My television suddenly shows a completely black picture, yet the audio still plays. I power-cycled the set but it made no difference, and I’m not sure where to find – let alone tweak – any brightness or back-light controls on the remote... (Budget: £10 - £15 GBP, Jobs: Audio Engineering, Customer Service, Electrical Engineering, Home Automation, Instructional Design, Technical Support, Technical Writing, Troubleshooting)