Too few channnels

Look in main menu, set is now in the air band which is 2-13 and you want it in the catv or cable band.

Done with a remote by using "menu" button first and then in setup selecting auto-program to program all available channnels.

There should be also there in that menu a way to add or delete single channels.

try this:
With tv powered on, push channel + and action buttons at same time.
While still pushing action button, lift channnel + button and push POWER button until appear The user´s menu on the screen.
Now the tv was reseted at factory values.
To Do tv set up.

Sounds like you may have a stuck button on the tv causing uncontrolled selection or the Main bd is bad. Try hooking up a different source such as a DVD player to the same input on the tv. If the tv works ok you might have a bad cable Box as well.

Very vague , but do you have no sound thru antenna channnels as well as AV channels, if so you have an internal problem or the mute button might be activated.

Try hitting the input button on your remote.

See if fresh batteries help.

in the menu...you need to change the input to catv instead of air.this will solve your problem...BB

the remote need to clean pcb board ..... the chroma section pcb need to resolder loose parts such as resistor, capacitor or transistor that you may see on it.....

Try resoldering where the tuner mounts. Rca has had some problems with solder connections