Polaroid FLM-323B Television "loud clear batteries" Questions

clear loud audio sound thru the DVD for a moment and then it went silent again. Battery in camper had 2volts on it and I replaced with a new one. Remains to have clear DVD picture with no sound at all

...no signal. I used to be able to get the chanels, but when selecting HDTV on the input menu, I get a loud popping repeated from the speakers. If I select Menu and try and get to the HDTV section, as I ...