No iPod backlight; not the brightness option

No iPod backlight; not the brightness option

Ive read through the board and can't find an answer to this. My classic recently has been working fine OTHER than the backlight not working. Its NOT the brightness option in the menu, its on full. The light will come on if I reboot ipod with center/menu buttons, but will soon be back to not working shortly. I've also tried restoring and while it seemed like it might work, a little while later its back to not working. IDEAS???

thanks