The picture on my JVC TV is too dark

Question

I have a JVC TV - Model AV-32WFT1EK. Recently the picture has become very dark. I have the brightness turned fully up and cannot get a bright picture. The Contrast is set at half, Sharpnes works OK, Colour OK as is the tint . Eco mode makes little difference. TV is approx 5 years old. Is there a manual method of adjusting the brightness. (I have been using my remote)