I hooked the monitor to cable and the built in speakers work great. I hook it up to my computer and I get nothing. I WAS using some speakers I bought at Wal-mart and they worked and I had sound, but when I diconnected the monitor to take it to use on the cable, when I hooked it all back up just as I had it, nothing works again... not even the external speakers. I've changed the setup to 2/2 speakers and it still has no sound. I just can't figure out what goes wrong. I reset to factory default and that didn't work. I installed upgrades and that did nothing. This is so frustrating!!!!