On static discharges damaging electronics

[Potatoes__]

Hey so I'm not that well versed in electrical engineering stuff so hoping to get some insight from you guys.

 

Had a case yesterday - hanging out at friend's place, he has one of those bean bag chairs made of some ungodly synthetic material that builds up static charge. At some point the dude left the chair to show us some youtube vid and got properly zapped when he brushed against a metal case of a wireless charger standing on his table. So hard in fact that the TV in the opposite side of the room (displaying the image from the PC sitting on that table though) flickered for a second. Had a laugh and carried on, but some time after he accidentally pikachued that charger again but this time his keyboard (Keychron K2) straight up died. Only the charging light was working, but no backlight and no input or recognition by the system whatsoever. Just ded, while it was working 5 minutes ago. Factory reset key combination also did nothing.

 

I took it in, it had zero signs of life at my place too, but praise be to Keychron they have a guide to re-flash the onboard controller, figured to try it and luckily the board got resurrected and now is fully operational again.

 

Now the question is: how come? The whole topic of "static electricity vs electronics" is teeming with misinformation and like I said I'm not really knowledgeable in this area. The charger in question was plugged into the wall rather than the PC, not even in the same surge protector, but it was sitting next to the PC and the keyboard in question. Somehow the zaps affected the video output to the TV and borked the controller on the keyboard. So maybe the pulse caused some EM interference rather than traveling through the wires all the way to the PC and then causing havoc? If it was wired, then how come it punched through the PSU (not sure what model he has but his PC is high end) and the keyboard was the only thing that died and not say the USB hub connected to the board? Or maybe the USB cable running to the keyboard right next to the charger acted as an antenna and affected it bypassing the PC circuits, but I'd assume the USB wire is shielded? The dude also said that he has some grounding issues at his place and gets zapped randomly, but he's even less knowledgeable in this area then I am so can't say anything for sure. Would the lack of grounding plus shooting lightning bolts from rubbing your pants on furniture spell disaster for electronics?

 

Anyway, just being curious here and maybe someone has a dead KB they'd now consider restoring 

[manikyath]

he's sitting in a seat that fills him with static, it's not because you had the one zap with the charger that you didnt also zap the keyboard earlier/later on.

 

also, if you're building static that easily, might want to look at humidity, because it might be problematically low.

[SirGurke]

Most likely it wasn’t some huge surge going through the PSU and “choosing” the keyboard, but an ESD pulse messing with nearby electronics. A static discharge is very fast and can couple into cables, USB devices, ground, etc., so your theory about it upsetting the keyboard controller makes more sense than the power supply somehow failing to block it. The fact that the keyboard came back after reflashing also points more to the controller getting knocked into a bad state than the board being fully fried.

 

So yeah, TV flicker + keyboard dying is plausible from the same static-prone setup, especially with dry air / synthetic furniture / possible grounding issues. Not every device reacts the same either — sometimes the most sensitive thing is the only one that glitches.

[Potatoes__]

Thanks for the replies! Ironically enough, the climate in the region we live in is annoyingly humid already so moisturizing it even more might spawn some weird mold feeding on ESD 

 

But that's an option at least. And getting bro some new pants that won't charge him up over everything.

[Kisai]

11 hours ago, Potatoes__ said:

 

 

Now the question is: how come?

An electric zap will induce the "quick format" of flash media. So if the firmware was damaged, that was it.

 

Basically what you described was a ESD effect if more than one device not physically connected experienced some kind of interruption.

 

Basically ESD (Electrical Static Discharge) describes the actual discharge of static, which in the dark would be seen as a blue/white flash. Usually ESD destroys or damages whatever makes direct contact, which is why things like AIB's, CPU, and RAM will usually be destroyed by ESD, but USB/HDMI/DP ports might just cause the PC to lock up, as the USB will trip a circuit breaker or fuse.