Capacitor issues outside of home computers.

Lately I have been watching videos on Youtube about car/engine repairs and teardowns and came across one about a mint old Lexus that worked fine then just quit working, and then worked again. The issue that even the dealer could not repair after replacing thousands of dollars of parts was a bad capacitor in the ECM module.

Makes me wonder what other devices outside of desktop computers ended up junked because of simple capacitor rot (and also makes me dread ever buying a new car with dozens of computers for everything).

Around here the rust gets them first

I've replaced the large electro cap in a few microwave ovens. You might say 'why bother' but the ovens in question are early 2000s Sharp convection units. IMHO they have the best user interfaces of a microwave I've ever used (handle door rather than pushbutton, simple convection preheat/heat/power mix + duration operation, 1-minute start on pressing the cook button with no time input, +1 minute each further press, beep stops on door open) rather than a cheap quality modern micro.

I had an only eight-ish year old refrigerator go maddeningly insane, spontaneously beeping at random moments... which I eventually figured out were spurious fake button pushes on the temperature control panel that's normally hidden when the doors are closed, which is obviously bad. (One day the food compartment will be set for 38 degrees, the next day it's at 46...) Jumping straight to the end of the story, not capacitors, but that lead-free solder everyone complains about. I reflowed the solder for the wiring harness connector on the satellite board with the buttons and display (the actual computer is buried deep inside somewhere) and it's worked fine ever since. Sigh.

That said, I honestly think people are way too paranoid about "car computers". Sure, there are horror stories, but the fact is that cars with computers are for the most part immensely more reliable than older cars, in the sense of continuing to run optimally with no manual tuning for years as long as everything's vaguely in order, verses the constant fiddling the Rube Goldberg mechanical nightmares that used to lurk under your hood took. (I've also very much grown to appreciate how you can usually find out what's wrong with your car just by hooking a $20 dingus up to a plug under your dashboard in five minutes, verses the alternative.) Where I think computers in cars are poised to jump the shark is this new idea that automakers should be able to charge you subscription fees to use the mechanical features they already built into your vehicle.

Bad capacitors are nothing compared to the evils of late-stage capitalism

We had a Viking refrig go down a few years ago and it turned out to be a dead power supply. I didn't know it at the time, just that "the board died" and only found out when he came back to install the new board that it was just a power supply and not the brain box. I'll bet it was dodgy cap's.

Everything around you is candidate for capacitor issues.
Warning: You will break yourself relaizing that you are now in entropy hell.

There's a lot of hardware in industry that is failing form capacitor issues but an HVAC tech for example isn't going to replace one capacitor on a furnace control. He'll replace the whole thing and toss the board because it's not worth his time to lean how to fix them.

Most service centers are just board swappers because that is what they are trained to do. The problem with that is whole controller boards tend to be expensive, and eventually are unobtainable.

Re-capped the ECM in my old 1992 Ford F150. Leaking caps--replaced, made it run like new.
Heat pump compressor start/run capacitors are notorious for becoming empty cans in 5-6 years.
Caps in LCD monitor power supplies often go bad just from the heat inside of a confined space.
....

Which is why you constantly find nutty people like us with hoards of "defective boards". We know that eventually a solution will be discovered and then rather trying to hunt boards down again we have cored to rebuild.

I remember that magical day when the leaky SMD cap revelations in macs suddenly spanned out and made everyone realize at once that many, many other defective things were the result of the same smd lytics failing. You started seeing game consoles, VCR's and appliances we assumed were junk because there was no way an SMD lytic could go bad were suddenly THE reason why they were going bad.

I have a little CRT TV set that I use. A few years ago, the image width would slowly and noticeably change as the unit warmed up. With some compressed air, tracked it down and replaced a small electrolytic capacitor related to the deflection.

More recently, when I had it unplugged for a while, plugged it in, and immediately turned it on, it would start making a very loud buzzing sound. If I left it plugged in for a while first, it would not make the sound.

The sound was coming from the power relay. Looking at the schematic, I realized that there is an electrolytic capacitor in the standby circuit right after the transformer that is always powered when plugged in... and has been powered constantly for perhaps 30 years. The buzzing was the relay cycling with the AC power as the capacitor was no longer providing constant DC power when it was cold. Replace it, and all was well again. The remote control sensor, that I don't normally use, also started working again - powered through the same standby power.

Simple fix. Everyone else would just throw that sort of thing away if they hadn't already. I probably should replace all the other electrolytics on the main board, but there are a lot of them.

I think my biggest capacitor-plague victim was my first LCD monitor, a Viewsonic VX910 that I paid like $350 for. It lasted about 3 years and then wouldn't power up. The electrolytics on the board were bulging and burst, and replacing didn't help.

Ironically, I had passed the monitor almost immediately to family members, because I fell in love with a $65 21" Trinitron CRT (Sun GDM-5410) from the local university's surplus shop.

If your electric motor won’t start, most of the time is due to starter capacitor burnt out. It is so common that starter capacitor for many motors are easily accessible for replacement. I have to replace starter cap on my air conditioner a few years ago and heater fan motor last winter. Both were easily accessible.

It's a good practice to check the caps (measure them) on things like compressors every year. The things lose capacitance slowly and it's harder on the motor.

I got stranded with my '92 Civic at one point and it turned out to be the main bypass cap having leaked through a supply trace of the ECU. Easy fix, but unexpected. Lots of the others were bad too.

Might not have been the caps' fault, as the previous owner mentioned that he went through a handful of voltage regulators on the alternator over the years, the radio had a blown fuse and other damage internally even after the fuse was replaced, the speedo worked sometimes and other times decided it was exactly 70km/h regardless of speed, and the reverse switch was somehow logically inverted (reverse lights on in forward gears only.) I wonder if he tried to boost it with the cables backward.

I miss that car.

I've had piles of UPSes fail from bad capacitors, this last year I replaced 10-15 of them. Recapping them doesn't help, the bad capacitors usually caused other failures.

Also had security alarm panels go bad from leaking caps.