My HDMI port never worked for years no matter what I tried. I kept getting quotes for repairs for about $400-$500 to replace the board where HDMI port is located. After researching many forums, I found out that a Special Service Remote is used to enter a special CODE to reset the HDMI port,....the remote cost around $40.00 if you can find it......but.....I also found this solution that worked to fix the "Green Screen" of death.
Use your own remote control that comes with the TV: Turn the TV on, and enter the Service Menu. Select 2 for Self Check. Then turn the TV off, and after the fan turns off, unplug the power cord. Reconnect the power cord, turn the TV on, and the HDMI port is reenabled. I tried the procedure and it worked fine. I left the power cord disconnected for 30 sec before reconnecting.
Step by step:
1) Set to "0 minutes" using the [SLEEP TIMER] key. (2) Press the [VIDEO STATUS] key and [DISPLAY] key simultaneously, then enter the SERVICE MODE. (3) When the Main Menu is displayed, press [2] key to enter the self check mode. (4) Turn off the power by pressing the [POWER] key on the remote control. (5) Unplug power cord from TV for about 1 minute. (6) Turn on TV, test the HDMI.
At first my HDMI flickered every 30 or so seconds, then I made adjustments to to use 1080i or 720P on my devices, fooled around with the TV HDMI settings then it stayed solid......havent seen the Green after that,,works perfect!