Some basic LCD TV troubleshooting guide for HDMI-related problems
If your LCD TV is not responding when you turn it on, one basic thing you can do is switch it off properly, wait 10 seconds, then pull the TV plug from the power socket. After 1 minute, plug it back in and switch the TV back on. Hopefully, by some miracle, your telly is working again. If not, the next possible root cause of problems that you can look into are those that are related to the High-Definition Multimedia Interface (HDMI) connection.
HDMI is the best way to get high definition video these days, but it is so good that the content providers were worried their stuff would end up out on the internet, easy to copy and distribute. So they created this copy protection protocol, referred to as High Density Copy Protection (HDCP), which is like an electronic handshake system that validates the recipient of the digital signal. If the source recognizes the recipient display devices through HDCP, then video data will be sent. The problem, however, is when the HDCP process gets corrupted somehow. This will certainly will lead to bad or no video signals. This problem, although more prevalent in the earlier years of its life, can cause problems that may easily be fixed.
The following are some tips on how to troubleshoot such problems and the simple measures that you can do to correct them without sending the unit for professional help.
Problem no. 1: No Picture
If the screen is displaying nothing when you turn it on, turn it off and do a restart. Ensure that all connections are properly plugged. Pay attention to the screen. If you see a resolution notice then chances are that the DDC or the Display Data Channel line has made contact or has communicated between source and sink. This simply implies that the problem is most likely video-related and not your hardware.
Problem no. 2: Pink Screen, No Audio, Some Flashing
If there is no audio output accompanied by a pink screen, it might be a DDC communication error. To validate this, turn the system on while all the HDMI cables are plugged and properly connected. I suggest using shorter cables. If the system still fails to come on when you power up, try using different inputs. There’s a possibility that your cable box will work but your DVD may not or vice versa. This can happen because of stray capacitance on the DDC line inside the HDMI cable. This may actually be a hardware problem. Try getting a DDC line conditioner. These types of problems completely go away after a conditioning process.
Problem no. 3: Screen/picture Sparkling
This can be data transmission problems related to HDMI which are most likely cable-related. There is likelihood that the cable is underperforming due to excessive length. This is quite a common problem with sub-standard and cheap cables. The rule of thumb is that the cable length should not be more than 10 meters. Shortening the cable should improve the signal quality. Another possible cause is a bad connector. HDMI connectors are notorious for this very common flaw. Try a new cable at each position along the signal path and see if that fixes the problem.
Problem #4: Video Comes On, Then Goes Off
One of a couple of things may be causing this. One, when one or more of the video Transition Minimized Differential Signaling (TMDS) channels has a high bit error rate or is totally not working. Two, when the DDC line does not quite make it. In that case, the High-Bandwidth Digital Content Protection (HDCP) is not getting a new refresh key. Use larger cable/wires that are of good quality. Get wires that have bigger diameter.
Video issues with your LCD TV can be caused by many possible things but it is best, for the sake of your wallet, to eliminate the most simplest ones first before you start spending money for a replacement or repair. I suggest performing these simple troubleshooting steps first.
This article was written by Steve Faber of What is the Best LCD TV Guide
If your LCD TV is a Polaroid FLM 3732 then see these Polaroid LCD TV Troubleshooting tips.
HDMI Cable image courtesy of http://www.konecable.com/
If you wish to learn more about how to repair LCD TVs all by yourself, please check out this LCD Television Repair Membership Site.