hoping to replace the right part based in symptoms

[computer guy]

hi, i have an rca flat screen tv that has no video or sound but menu and volume bars show up fine. with doing a little research it seems my best guess is the av board is bad. I am looking to purchase one but dont want to waist money if I am wrong. I am willing to take a chance if someone that knows these symptoms and would agree that it is most likely the av board. hoping you can let me know if im on the right track thanks inadvance