When HDMI Cables Short Out a System

I recently received a letter about a system failure that appeared, at least at that time, to be pretty scary.

After the initial installation of a DVD player and a display, a funny smell began to emerge out of the system. Concerned, the installers shut the system down and replaced the DVD player, where the smell seemed to be coming from.

You guessed it; the smell came back. Now they were really confused.

So they replaced the display. Again, the smell, which they later found out was a burning smell, came back.

I instructed the installer to go out and get a diagnostic tool to verify that all the handshaking was taking place. When the testing device interrogated the buss, it found there was not sufficient supply voltage (5 volts) on the buss. This told me right off that the voltage was being dumped, killing both the voltage and the system.

After just a little phone work, I determined that the problem was in the cable or cables the installer used to set up the system.

The only problem was that the cable in question was in the wall! Not good.

They installed a new cable and the problem stopped. It turned out that one pin inside the HDMI connector was shorted to ground -- pin 18. That is the 5 volt supply line. Fortunately, the DVD was built like concrete and was able to maintain its own internal supply and not become damaged.

The first lesson when installing HDMI cable is to check the cables before you install in a wall. There are HDMI testers out there you can pick up for cheap or just run the cable before you go to the job sight.

Jeffrey Boccaccio, principal, InVisions Technology, can be reached at .(JavaScript must be enabled to view this email address).