Zenith IQB32B42W 32" TV works sometimes but looses picture. Top half of picture goes blank (dark) and the bottom half scrambles into horizontal lines. I hear a pop or click right before this happens. The TV will go off if it happens for too long of a time. Some times unplugging and plugging the TV in again will cause the TV to work again. Any idea as to what is happening and is it worth fixing?

SOURCE: Auxiliary button on tv remote (I believe) needs off and I can't get figure out how...

The remote should have TV, VCR, AUX and maybe CABLE buttons at the top, one of which will light up when any button is pressed. Since it is a universal remote, the button at top lights up to let you know what mode it is in. If the AUX button lights up when any button is pressed, it means the remote is currently set to the AUX mode. To set it back to TV, simply press the TV button at the top. This puts the remote back in the TV mode and the TV button should now light up when any button is pressed. If that works and you are using a cable box with that set, then make sure the TV is on channel 3 by pressing 3 ENTER.

SOURCE: TV went "pop"

prob not worth repair sounds like horiz sweep circuit. 150 200 to repair. 

SOURCE: Horizontal lines across TV screen Panasonic CT-31SF13U

The problem sounds like a vertical deflection issue form what you describe.
On average they are usually in the simple repair categories. On average they would run in the $50 range if you take it to a reputable repair shop.
There are several possibilities
Bad capacitor (s)
Bad vertical IC
resistor in the power supply to the vertical circuit changing value

SOURCE: Zenith tv picture jumps after 20-30 min.

the variations of the supply causes that. a verticle stability be checked, specially semiconductors and capacitor changing valuas
Q= CV
Q=IT
THEREFORE

IT=CV=Q AND frequincy = f=i/t
so if I AND T CHANGES CAUSING MOVEMENT OF PICTURE

SO I is for time and T for tempareture