md301b MAGNAVOX LCD controls dont work no remote

[Packard93]

I bought tv that has buttons dont work .But when Im able to get hdmi input selected it will work . But I cant use the buttons after a few seconds to a min they stop. They way I get it to switch is using any my old main but it get locked too into dvd mode . When I get it to switch with old board I switch back to new board and I select my hdmi 1 input for my time warner box I get a great pic and sound but after 1 min the controls for sound and menu power any button on tv is inoperable. . Ive been trying to diagnosis tv . md301b MAGNAVOX LCD controls dont work switch boards works temporary tv has a dvd player that spins but dont show pic when I locks into the dvd switching boards is the only way to get back to hdmi and then i can get volume buttons work temporily after i have output I leve it at that. But buttons on tv dont work after a min of tv . The tv has a dvd /combo that it get stuck in and I cant switch unless i switch my mainboards. then I switch on either board temporarily. Dvd causes issie Im thinking but I dont know where should I test with multimeter?

[kc8adu]

Re: md301b MAGNAVOX LCD controls dont work no remote

leaky tact switches.
do you smoke?
replace all the switches on the button assy.

[Packard93]

Re: md301b MAGNAVOX LCD controls dont work no remote

after further diagnostic I took my multimeter checking to see if voltages would change when button was depressed . I seen decreases in voltage meaning buttons were functioning. So I decided to screw with the dvd player some more dvd spit out and I noticed for split second again the buttons worked as I was power up. So I remember reading the service manual . It said you should be able to get a manaul eject. so i pushed the mechanism and got it to fully extend as it should . Now all buttons work and I switch inputs menu sound up/down all ok everything power button ok menu ok . I checked to see if problem would come back it has not tv performing perfectly . This happened with dvd fully extends out the disc tray. Im think it changes the output voltage to the board when it extends out. And it was waiting for the voltage . Its like the computer in my car they set code in a car though like output voltage does on tv but no code. INPUT AND output voltages have to be set a certain way. That tray extended made tv buttons work flawlessly.