Brand new. No sound from any speakers or headphone. Headphone indicator is on without headphone jack inserted

These are analog speakers and do not need a driver. First, make sure they're plugged into the speaker/headphone jack and not the microphone jack. Second, make sure the computer's sound output is enabled and set the headphone/speaker jack. Third, verify that the sound output is working by plugging in a headphone set or a different pair of speakers. If the computer sound checks out, the speaker cable is bad or the power supply is not working.

The speaker cutout feature whenever the headphone jack is connected is a hard-wired feature of the headphone connector, and cannot normally be bypassed without further electronic circuitry and the associated surgery to install a custom modification in the TV. In order to keep the TV speakers on while using the sound elsewhere, you will have to take the audio output from the IR Audio port, if there is one.

No the headphone jack doesn't disable the speakers. There are two switches in the lower middle of the receiver that are labeled speaker A and B. Pushing one of these should disconnect the speakers from the receiver.

Take the audio out from the audio output RC jacks (Red and White). Then connect a headphone into the headphone of the TV. The speakers then will then get off. Never insert a dummy stereo jack, as the amplifier without speakers can get damaged (depends on the audio IC used).

So it IS acting like headphones are inserted even without them. Stop messing with other connections. The jack for the headphones has spring-loaded normally opened and normally closed contacts that are designed to disconnect the speakers when the plug is inserted. Perhaps the NC connection isn't making good contact on headphone removal. With the Volume turned to soemthing NOT LOUD, repeatedly insert/remove the jack to see if it makes any difference; or with power OFF squirt a little tuner cleaner in there first and repeat with the headphone jack.

It is a mecanical problem, not in settings. The laptop's headphone jacks have builted-in switches that disconnect internal speackers when the headphone jack is plugged in. You need to replase headphone jack with a new one or manually desactivate the swith - must to get ino your laptop and have skills in work with soldiering iron

Try the speakers on another computer, to see if they work at all. If they do, then the problem is the audio-interface on your computer (or DVD-player, or home-stereo system).

The lit indication ("amp bars") proves that the aduio signal is getting through the unit's circuitry @ least to that point; lack of sound @ the spkr & headphones indicates the amplifier portion of the circuitry is either inoperative or disconnected from the load (i.e., either the speakers, or the headphones). A common cause of this type of problem cropping up unexpectedly is the headphone jack itself; in most products of this type, the audio path from the amplifier output to the speaker connection runs through the headphone jack, so the the speakers may be "turned off" when the headphones' plug is inserted into the jack. If the unit's owner uses headphones regularly, the most common problem to be found with the jack is loose solder connections to the printed circuit board's traces from the jacks' lead(s); in units with this problem whose owner's irregularly use the headphones, it's more common to find oxidization of the electrical contacts within the jack itself.

No it's not possible to have a sound. Because the HDMI and the Headphone (3.5mm jack) are on two different technologies.

The monitor does not have a way to convert the sound from HDMI to Headphone.

There could be a converter that might convert the sound signal from HDMI to headphone (but I'm not sure).