I am using HDMI to VGA converter to connect laptop (HDMI) and Projector (VGA port). I get video display through Projector (Epson Home Cinema 1040). I want to play sound through HTS. If I connect 3.5 mm jack of Laptop with RCA (Red and White) to projector, there is no sound. Probably it is due to HDMI (to VGA converter) connection in Laptop. If i connect VGA cable directly from laptop to Projector, message comes that there is no signal from computer.
The projector has following ports: 2 HDMI, 1 RCA (Composite), 1 RCA(1 audio L/R),1 VGA and USB. HTS has following ports: 2 Optical, 1 HDMI (out), 2 RCA, 1 Composite
The laptop is probably set to output audio via HDMI. Change the audio device to the headphone jack and you will get sound.
I assume you are using the projector VGA input because you have the long VGA cable and not a long HDMI cable. You may have to turn the laptop VGA output on in the graphics control panel. Unlike HDMI it's not automatically detected by the laptop. Make sure that the video resolution is set to the best VGA setting which may be different than HDMI.
You can get the projector manual here https/epson.com/Support/Projectors/Cinema-Series/Epson-PowerLite-Home-Cinema-1040/s/SPT_V11H772020