LG 37LD490 TV. No picture but sound on Game and DVD inputs. Main HDMI input is fine.

Verify what input source your LG television is on. Using buttons on the tv or the remote you can change the input source. The input you want to choose needs to match the connection type of the dvd player. For example if you are connected using HDMI, than you will want to choose HDMI from the input source menu. There may be more than one HDMI so be sure to try each one.

the avi board is separate from the the hdmi board. would say there is a fault with the avi board may need replacing or may be able to fix it.

I have the same problem. Good picture with no sound at all. I have a LG DVX583KH and LG TV LM7200. I connected the DVD player to TV via HDMI cable, I have a clear picture but no sound. I try to hook up the DVD to other TV and it works both sound and picture. Please help

LG documentation states:

When you use SIMPLINK function, you have to

connect to the OPTICAL IN 1 jack to enjoy TV
sound to your speaker system.

Basically you need to have the Audio go from TV to receiver and setup receiver to that Input to output surround sound to all speakers.

If you have a cable box or satellite receiver, hook that output into the receivers input and that should work.

My setup is DirectTv HDMI output goes into the LG Home Theater HDMI Input 1, and LG goes HDMI output into the TV HDMI input 1.
so to watch DirectTV, I switch LG Home theater to HDMI Input 1. and TV is on HDMI input 1 (to view LG HDMI output from DriectTV, Blu-Ray, Vudu, etc.)

Hello,
There are two things that I can suggest.
1-Test your optical cables to make sure they a good on a known working source because they are very fragile and break very easily.
2-Try to eliminate the use of optical output from tv to receiver. There may be a problem from the HDMI to optical conversion at the tv. Instead, try running the audio directly from the source to the receiver, and let the tv deal with video input only.
Hope this helps,
Good Luck.

I solved the same problem by disabling SIMPLINK from OPTIONS menu. I own the LG TV myself. The LG TV comes SIMPLINK "ON" as default setting from the factory. Go to MEMU -> OPTIONS -> Turn SIMPLINK to "OFF". This should work....

if the Comcast cable box has an HDMI output, it should connect directly to one of the TV HDMI inputs. Then connect the LG DVD unit HDMI output to the second HDMI input of the TV. Use two HDMI cables. Do not buy the expensive Monster HDMI cables. If you have already done so, I recommend you take it back for a refund, then buy the low cost HDMI cables which will work just as good and then you can bank the savings toward a new Porsche Boxter!! Now we have the video connected from both the cable box and the LG system.

Now--what do you do if the cable box does not have an HDMI output--just use its component output and your component cable (red, blue and green) to connect to the TV component input. This will still get the video to the TV and good HD pictures. Hum--do you have an HD cable box? You did not say and I just assumed that you did since you got the HDTV. If not, let me know with a follow up question and I will assist in that area further.

Now for the audio connections--The DVD player will not need any connections since it in the LG unit. The sound will come out the speakers when you start playing the DVD. The cable box is where we get the TV audio to feed the LG unit. If the cable box has an optical output, use an optical cable (again the low cost one)and connect to the optical input on the LG.
This will get the TV audio to the surround system. If no optical output, use the red and white (left/right) audio connections and connect to one of the two the LG audio inputs. To hear TV audio on the LG speakers, just switch to that input or the input associated with the optical input.

To watch DVDs, switch the TV to the HDMI input to which you connected the LG unit. For TV, go to the other HDMI input (or component input).
Switch the LG to the audio input to which you connected the cable box to get TV sound.

Hope this gives you food for thought. If so, and you have more questions, just come back in with a follow up.

Have you tried another HDMI cable? The cable may be bad. However, if this is not the case and this is happening across mutliple devices(cable box, dvd player, etc) then you might have a bad HDMI input on your TV. Does this happen on all HDMI inputs on your TV? If you can safely rule out your other devices and the cable itself then you've got a main board problem and would need to get it replaced. 

what type of input and device are you using? what type of connection? HDMI, Component, AV? DVD player, VCR, Cable/Satellite? Using HDMI will give you the best picture and sound. Best way to test is with a blueray or DVD player using HDMI input. If your picture is still bad, change the main board.

green screen on hdmi is normally a defective hdmi cable. 1st try a different device , like a dvd player. if same problem try dif cable. if it still does not work you have a defective signal pcb otherwise known as a main pcb.