I am connected lg dvd 5.1 to home theater but only two speakers nd sub woofer working 3 speakers are not working.,what am do?

Most receivers have setup menu where one can check that connections are OK. In order to hear all five speakers, you must provide surround source (eg DVD movie with surround sound), or use your home theather' options to simulate surround from stereo signal.
Jun 27, 2018
The solution is simple, there is LG EQ and EQ button on the remote control of the home theatre, use the button to switch to NAT PLUS or BASS BOOST, those are the only two modes that support all speakers sounding at once.