MaleGigolo wrote: ↑16 May 2022, 12:19
If you are so sure about issue being electromagnetic interference Chief has said multiple times
It's best not to paraphrase me --
never -- always link to original posts.
Because of
The Famous Chinese-Whisper Problem, where information keeps getting distorted when parrotted as second-hand or third-hand information.
It's practically true in certain contexts, but false in other contexts.
I never said EMI can't damage equipment -- it is just highly unlikely when I narrowscope it to things like low-voltage wires next to ordinary power wires -- since that's lower-level interference than a lot of kinds of EMI that can actually do damage.
Nuclear EMP definitely damages equipment, as well as an EMP from an MRI (e.g. if you accidentally put a smartphone inside a powerful hospital scanner -- they can go dead).
Twenty years ago, I can tell you a true story where an EMP from one gadget damaged another gadget.
I actually accidentally bricked one of my BlackBerry pagers in year 2002 from an xenon camera flash -- I never knew that large xenon camera flashes (especially with 1990s-era transformers) could generate an EMP/radiation powerful enough to damage a silicon chip that was held millimeters from it (I was holding the BlackBerry against the flash while using the flash.
It might have been as simple as single flash-memory bit flip from X-ray radiation emitted from the Xenon tube (old Xenon tubes sometimes went to voltages high enough to emit a small amount of X-rays). But that did not matter -- the BlackBerry 950 pager was dead, and would not respond to a firmware reinstall. Screen instantly went blank the moment the camera flash went off just millimeters away from it.
Many gadgets of yesteryear emitted larger EMP -- such as malfunctioning cathode ray tubes can emit a lot more X-rays. But it can happen to any ultra-high-voltage tube like neon tubes or camera flash tubes, or even certain kinds of vaccuum tubes before transistors.
(X-Rays is one of the many possible forms of EMP -- can be any frequency, radio, microwave, X-Ray, gamma, visible light, infrared, etc. Sufficiently intensely bright, it can do unexpected damage to nearby gadgets). Yesterday, that's why they told you not to put things through an analog airport X-Ray machine. But once digital X-ray machines arrived at airports, they had 90% less strength to get vastly superior high-def X-ray images, and newer electronics/films tended to be more X-ray immune.)
However, modern xenon flashes no longer do that since they now use solid-state electronics that don't go as high voltage, and use smaller xenon tubes that don't need as high voltages (that generates X-rays).
P.S. Yesterday's AC adaptors (copper-winding transformers) is a form of using EMP to change voltages. One winding injects a field into the ferromagnetic core of a transformer, and another copper winding (fewer windings or more windings) picks up this and changes this EMP back to a voltage. So your old heavy cube-shaped AC adaptor (from 30 years ago) is an "intentional EMP/EMI" to change one voltage to another voltage. This was the days when copper was still cheap and switching power supplies was still ultra-expensive. In some cases, a malfunctioning AC adaptor mere millimeters or an inche away from ultra-sensitive electronics, have caused some weird effects or even damage (e.g. bit flips in early EEPROM chips), like AC adaptors on a power bar flush against old sensitive electronics inside a tight-fitting cabinet, etc.
The bottom line is that it is extremely rare for EMI to damage a modern computer, especially since most EMI/EMPs are extremely weak after a few inches of air (unless it's a big field emitter like a giant unshielded CRT tube before the lead-glass days ... or a hospital scanner ... or a nuclear bomb .... etc). However, it is not a zero chance. Any EMI/EMP that goes over a low-voltage wire (short of a direct lightning strike to the wires attached), the wire is generally incapable of emitting enough EMI to permanently damage a computer directly except
indirectly from rube-goldberg dominoe effects (e.g. interrupting or corrupting an in-progress flash memory upgrade as an example, in a situation where there is poor fallback logic to previous firmware, etc) --