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Originally Posted by whinnycritter /t/1331747/hdmi-surge-suppression#post_23566840
I'm now dealing with the second HDMI lightning damage within 3 years. Fortunately, I'm a technician with 45 years experience, so I'm able to replace the HDMI interface chip in the TV again. This time it also took out the HDMI port on my DISH receiver. I've also lost several HDMI switches. NOTHING is getting to my equipment by way of the power line! I have a whole-house arrester on the pole, below the meter, then a Tripp Lite outlet box that boasts $50,000 guarantee for connected equipment, then a Topaz sine-wave UPS, then another Tripp Lite, then another outlet strip with surge suppression. But here's the deal. A very close lightning strike produces an electromagnetic pulse (EMP) that will induce thousands or even tens of thousands of volts into ANY nearby length of wire. In addition to HDMI ports, I've also lost the PS2 port on a computer motherboard, along with the connected KVM switch, several ethernet ports, and an expensive video server. So, what can be done? You can start by using the shortest possible cables. Monoprice has HDMI cables as short as one and a half feet, and they have ferrite cores at each end (which may not help, but can't hurt). Second, you can use a sacrificial device, such as an HDMI switch or an extender/booster. Let the circuitry in these cheap (less than $20) devices take the hit. With luck, they won't pass the spike through to your expensive equipment. I'm not sure whether the power available on HDMI will handle multiple devices, but I'm going to give it a try and will post my results here. As for the surge protection built into HDMI ports, yes, these chips do have it, but the problem is not just volts, but energy. That's volts X amps X time. The chips will protect against fairly high voltage, but not many amps, or not many microseconds. That's fine for static discharge, but lighting induced surges involve a LOT of energy, that can overwhelm the protection that can be built into a chip. MOV's that are used in outlet strips can handle it, but they have lots of capacitance, and cannot be used with high-frequency signal lines, as that capacitance will act as a short circuit to those frequencies. As for the available HDMI surge supressors, as yet the price is just too high for me.