A black box appears every time I have the TV on. covers 90% screen, other video is observable on remainder of screen.

Clicke remote and the box does away for a few seconds.

MY ONLY TV and my little girls are sad.

19" Magnavox

model # 19PSC50121

Serial # 36869988

This does not work:

To disable the Demo mode, perform the following:

1. Turn on the TV.

2. Simultaneously hold down the Vol+ and Vol- buttons on the front of the TV. Do not use the remote control.

3. Hold for about 6 seconds

4. Certain model TVs may turn off, others will not. But in either case, the Demo mode should be disabled.

All should be well after these steps have been followed.