It happened in 2014. A year later, it happened again. And after a nine-year blessed respite, a month back it happened a third time. What am I talking about? Close-proximity lightning (each time unknown whether it just cloud-to-cloud arced overhead or actually hit the ground) that once again clobbered some of my residence’s electronics. Thursday night, August 8, we scored a direct hit from a west-to-east traversing heavy rain, hail and wind squall. When the house shook from a thunderclap seemingly directly overhead, I had a bad feeling. And the subsequent immediate cessation of both LAN and WAN connectivity sadly confirmed my suspicions.
As background for those unfamiliar with my past coverage, I’m the third owner of this house, located in the Rocky Mountain foothills just southwest of Golden, CO. The previous owner had, when retrofitting the residence to route coax and Ethernet to various locations in both the ground floor and upper level, gone the easy-and-inexpensive route of attaching the cabling to the house’s exterior, punching through rooms’ walls wherever interior connectivity was desired. Unfortunately, that cabling has also proved to act as an effective electromagnetic pulse (EMP) reception antenna whenever sufficient-intensity (strength and/or proximity) lightning is present.
This time, a few things—one of our TVs that initially no longer “saw” any of its active HDMI inputs and the exercise treadmill whose motor stalled—were temporarily stunned until after I power-cycled them, after which time they thankfully returned to normal operation. Alas, other gear’s demise was more definitive. Once again, several multi-port Ethernet switches (non-coincidentally on the ends of those exterior-attached network cable spans) got fried, along with a CableCard receiver and a MoCA transceiver (both associated with exterior-routing coax). My three-bay QNAP NAS also expired, presumably the result of its connection to one of the dead multi-port Ethernet switches. All this stuff will be (morbidly) showcased in teardowns to come.
Today, however, I’ll focus on the costliest victim, the control subsystem for the hot tub on the back deck. In the earlier 2014 and 2015 lightning incidents, we’d still been using the home’s original spa, which dated from the 1980s and was initially located inside the residence. The previously mentioned second owner subsequently moved it outside (the original “hot tub room” is now my office). The geriatric hot tub ran great but eventually leaked so badly that in 2019 we went ahead and replaced it. In retrospect, I remember having a conversation with the technician at the time about how its discrete transistor-and-relay dominant electronics would have likely enabled it to run forever, but for physical integrity compromise that led to its eventual demise.
After the storm calmed, on a hunch I went outside and lifted the hot tub cover. The control panel installed on the hot tub rim interestingly was still illuminated. But the panel itself was dead; the display was blank, and the control buttons were all inoperable. Curiously, the hot tub pump (and presumably other subsystems) also seemed to still run fine; I could hear the motor kick on as normal in response to each power activation cycle, for example. But not being able to adjust the temperature and pump speed, not to mention alter the filter cycle settings (and the clock settings they’re based on) was an obvious non-starter.
Unfortunately, the manufacturer’s three-year warranty had expired two years earlier. More generally, production on this particular control panel had ironically ended roughly coincident with when I bought the hot tub back in 2019, and my technician was no longer able to source a replacement. This meant that, although there was a chance that only the comparatively inexpensive control panel had gone bad, I was going to have to replace the entire “pod” kit that included (among other things) a newer model control panel. Here’s what the old “pod” looked like after my technician pulled it out and before he hauled it away for potential spare-parts scavenging purposes; according to him, the blue cylindrical structure on top is the water heater:
And here are some closeups. The large square IC at the center of the last one, for example, is likely the digital control processor. Unfortunately, its markings have either been intentionally obscured or were otherwise too faint for me to be able to discern:
I unfortunately don’t have any comparative pictures of the original hot tub’s electronics, but trust me, they were way more “analog”. Feel free to chime in with your thoughts in the comments as to the comparative reliability of “oldie but goodie” vs “shiny new” circuitry…
Now for the removed old control panel:
And its installed and operational successor:
So, what happened here? As setup for my theorizing, here are a few more old-panel photos:
Originally, there were actually two cables connected to the panel. One, not shown here, was a simple two-wire harness that, I hypothesize, ran power from the “pod” circuit board to the panel’s LEDs for illumination purposes. As I mentioned earlier, it seemingly survived the storm just fine. The one shown here, on the other hand, is a multi-wire cluster that terminates at and connects to the circuit board via the connector shown in the second-photo closeup.
This particular cable was, I believe, the Achilles heel. Its signals are presumably low-voltage, low-current digital in nature. Remember my earlier mention of Ethernet cables (for example) acting as EMP reception antennae, with disastrous equipment consequences? I’m guessing the same thing happened here, via this foot-or-so long multi-wire harness. Did the EMP only fry the control panel’s electronics, versus also damaging the “pod” board circuitry? Perhaps. By analogy, in some cases over these three (to date…another heavy-thunder storm is ironically brewing as I type these words) lightning-damage episodes, the Ethernet switches on both ends of a particular outdoor cable run have died, while in other cases, only one switch has expired. Regardless, given the replacement parts-(non)availability circumstances, it’s a moot point.
I’ve got more to tell, including the already-mentioned teardowns, plus (for example):
- How I resurrected my network storage, in the process bolstering my file backup scheme
- Options (some of which I’ve tried, with varying degrees of success, and documented) for dispensing with the outdoors-routed Ethernet and coax cables, and
- Residence-wide surge protection schemes
For now, however, I’ll wrap up this post’s topic focus with an as-usual invitation for readers’ thoughts in the comments!
—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.
Related Content
- Lightning strike becomes EMP weapon
- Devices fall victim to lightning strike, again
- Ground strikes and lightning protection of buried cables
- Teardown: Lightning strike explodes a switch’s IC
- Teardown: Ethernet and EMP take out TV tuner
- Teardown: MoCA adapter succumbs to lightning strike
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