My name is***** will assist you. I am sorry to hear that you are having this issue.
This is usually caused by a glitch in the firmware and can be resolved by a software reset then your Toshiba will work normally again. Choose the software reset in the menu. Press the up down arrows to select Reset, choose ok, a screen will appear warning that all settings will be lost, press ok to continue. When the tv powers back on choose quick setup to retune the channels. Please let me know if this does not work for you, or if you need any other assistance.Please take a moment to rate my service positively.
Thank you very much!