More information is needed.
Make and model TV? Age? Condition? What connections are being used?
Do you have the User Guide/Manual?
If not, check the manufacturer's website.
Look for the applicable User Guide/Manual.
Determine the meaning of the blinking red light.
Run any suggested troubleshooters.
Check the sites FAQs and Forums - someone else may have the same problem and a solution could be available therein.