I have a magnavox 19md357b/37 - orig remote not included. the tv turns on, get picture just fine. the sound button on top turns the sound down, but as soon as you release the button, it increases to the maximum limit. the menu button on top doesn't seem to work but the channel button does. the power button turns tv on, but have to use universal remote to turn tv off. help?

Marilyn, May 2012