when is the last time you had a electronic catastrophic failure in your home? - Page 1
Forum section: electronics / general

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 22, 2014, 07:10:37 am
content: So I was working in my lab late one night when i came across an eerie sight (well actually it was like 6pm).... well a occasional flicker, which should have clued me in... but then a smell... so I thought oh great, one of my eBay test equipments must be frying... but then I realize the rigol is the only thing on and it does not smell bad.. the computer smells fine.. hmm, something is making the room light flicker and making something smell bad... maybe something is wrong with the mains and its causing some thing to fry...the smell gets stronger and stronger... and everything goes dark... duh, the fluorescent light bulb failed. It was still smoking after the light stopped.I have yet to tear it down but it looks like there was a short on one side of the tube, melting the area where the glass coil was making contact with the plastic housing, and charring it.I don't know if the light bulb could have potentially ignited, but it is only 8 or so inches away from the ceiling... hopefully it cannot burn with enough force to ignite the insulation behind the ceiling sheetrock. I replaced all of the light bulbs of that brand in my house and now I am going to go on a witch hunt for chinese power supplies and other hazards...but now I am paranoid. fuck the energy savings if that crap can burn my house down.... I'm keen on replacing all my fluorescent lamps with incandescent lamps... or at least magnetic ballast lamps.. and linear power supplies...If I feel asleep in a room with that bulb with the lights on I would have undoubtedly received a nice dose of healthy carcinogens...do they make some kind of fluorescent bulb that has a ceramic, glass, clay, teracotta housing ?I don't see why they can't make the bulbs out of a terra-cotta pot material.. or wall warts/laptop chargers. I would accept the fragility in exchange for safety. Hell, id feel more comfortable with a metal housing then this plastic, at least then it only kills you if you are a drunken idiot (at least for a light bulb).granted, that plastic should be non flammable, but if their QC for the plastic is as reliable as it is for their driver electronics then I expect the plastic to melt into napalm.

author: AndyC_772
author_rank: Super Contributor
timestamp: April 22, 2014, 07:38:19 am
content: Why not try igniting the plastic and see what happens? It should be UL 94V-0 rated, which means it's self-extinguishing within 10 seconds and cannot produce flaming droplets.I wouldn't want a mains powered device like a laptop brick to be in a brittle ceramic enclosure. It's fireproof, sure, but one bump and you've exposed the live internal connections. It would fail CE drop testing which is designed to test for exactly this type of hazard.Energy saving bulbs are all about return on investment. If they cost more than the power they save over some reasonable period of time, then they're not commercially viable. It's no surprise that the commercially successful ones are cheaply made, electrically noisy, and unreliable.

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 22, 2014, 07:44:37 am
content: Quote from: AndyC_772 on April 22, 2014, 07:38:19 amthats true. I intend to eventually try to ignite the plastic and see if I could determine what actually failed in the light bulb.But still... that smell cannot be good for you. At least if it happens in the lab you can throw the windows open and evacuate quickly. but if its some damn thing thats running while you slumber...at least its a wake up call the install more smoke detectors.and, how about the parts inside turning into napalm? Even a drop could be disastrous depending on the situation.

author: amyk
author_rank: Super Contributor
timestamp: April 22, 2014, 08:00:03 am
content: That is a well-known failure mode of CFLs, and it is normal...http://www.ul.com/global/eng/pages/corporate/newsroom/storyideas/compactfluorescentlamps/Tons of other pictures/stories of them burning out like this here:http://www.execulink.com/~impact/fluorescent_lights.htmIndeed it does look like the plastic is 94V-0, as in almost all of them you just see melting/charring, althoughthere are some OHL brands that don't use flame-retardants...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 22, 2014, 08:06:17 am
content: Last failure I saw wasn't at home, and technically not even at work, though it affected work that day. In the morning, the lights were flickering occasionally; by afternoon, there were rolling brownouts (and the din of irregularly beeping UPSs in the office) before it finally switched off.Turns out a power pole (7.2kV or thereabouts) across the street was lightly arcing across the insulator!Tim

author: Rerouter
author_rank: Super Contributor
timestamp: April 22, 2014, 08:08:35 am
content: Had a capacitor detonate in a very cheap AC LED light bulb, internally shorted the socket and threw the whole house into darkness when the lighting breaker tripped,All this happened when i was at the other end of the house, so from my point of view i hear an almighty bang, (if you have blown up a big enough cap they start to sound like a round out of a big gun) the house plunge into darkness and a very heavy smoke smell creeps in from that side of the house, which by that point i really started wishing i had a fire extinguisher in the house (now do)

author: IanB
author_rank: Super Contributor
timestamp: April 22, 2014, 09:06:37 am
content: Quote from: T3sl4co1l on April 22, 2014, 08:06:17 amThere is more than one video on YouTube where the high voltage has shorted across to the low voltage side of a pole transformer and the resultant arcing in the mains supply cable has set fire to houses. The worst thing is that the fire department won't tackle the fire until the utility company has managed to turn off the power. That would be the worst kind of catastrophic failure I can imagine.

author: VK5RC
author_rank: Unknown
timestamp: April 22, 2014, 09:33:27 am
content: I don't think its quite in the correct category but my childhood home was in a high lightning area, EVERYTHING was always unplugged if you weren't using it. I think in the 40 years we were in that house we went through 7 or 8 telephones (in those days you had to rent one from the telco, so we tended to leave it plugged in).One big zap (a tree about 20feet away from the house got a direct hit- it held up the phone line as it entered the house) not only did it fry the phone but also my fathers old HP45 calculator charger 3 feet across the desk from the phone! Lucky he wasn't sitting at the desk at the time.Recently while mucking around in my shack, the magic smoke arose from a stack of nice but old gear, the transformer on a HP 85640 decided to die at that moment.I am not sure linear 'stuff' has a much lower fire risk than SMPS, I suspect quality and age are bigger factors; good fusing is obviously really important.

author: rollatorwieltje
author_rank: Unknown
timestamp: April 22, 2014, 10:05:32 am
content: Some nasty decorative LED light string. It plugged directly into the mains, and had a tiny controller box. Turns out the mains cable didn't have any proper strain relief, not even a damn knot in the lead. Needless to say the soldering on the PCB broke off and started mayhem, not quite shorting out but drawing stupid amounts of power, so the 16A mains breaker didn't trip. I think the controller itself had a fusible resistor on board, but that's obviously useless when the mains cable is flapping around.

author: KJDS
author_rank: Super Contributor
timestamp: April 22, 2014, 10:48:47 am
content: My girlfriends electric toothbrush died. A recently purchased £80 toothbrush but she'd lost the receipt. Fortunately it was just a sticky on switch but getting into the sealed housing was fun.

author: Rerouter
author_rank: Super Contributor
timestamp: April 22, 2014, 12:35:22 pm
content: 80 Pounds for a toothbrush? i am impressed, especially considering it failed soon after purchase, guess the old saying of "sell for twice as much to the person willing to spend twice as much" still applies,

author: Biff383
author_rank: Regular Contributor
timestamp: April 22, 2014, 01:27:02 pm
content: Last ice storm (Dec.20-13) power before the transformer shorted to the house wiring. .... i heard it and noticed the lights go out but SWMBO was outside at the time and saw the fireball make it almost to the house. Spent the next 5 days in a motel till they got the power back on. Kinda makes you wanna go solar. I don't know why it didn't fry all the electronics in the house, but it was all fine.

author: GreyWoolfe
author_rank: Unknown
timestamp: April 22, 2014, 04:37:36 pm
content: Someone gave me an old rack mount tube oscilloscope (don't remember the name) that had no top or bottom cover. Took a chance (now I have a dim bulb tester) and powered it up. After a few minutes of being on, a crackling noise started and a 4" flame came out of the top of the scope.Of course, I pulled the plug immediately. The smell lasted in the house for a couple of days. SWMBO was not happy. Someone else recently gave me a Tek 533A tube scope that he said sat in a closet for a few years. I don't have the nerve to power it up being that there is a 10KV rail in it and I don't have a variac. I cleaned it up inside and out as best as I could and it is a conversation piece in my office.

author: nanofrog
author_rank: Super Contributor
timestamp: April 22, 2014, 04:38:11 pm
content: Squirrels chewed through the electrical service's neutral wire to my house. Fortunately, I only lost some wall warts as a result.

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 22, 2014, 05:03:51 pm
content: Is there any protection one can afford for HV mains going into your house? is it possible to put some kind of massive GDT/sparkgap/something in/near/outside at the entrance to your house/ the circuit breaker box?I heard this story from a fire fighter about this somehow happening (it might have been stupid electrical workers actually), and it did result in the house burning down. I think he even said the fire started at multiple points inside the house or something like this (but it was years ago I don't remember too well).

author: nanofrog
author_rank: Super Contributor
timestamp: April 22, 2014, 05:54:55 pm
content: Quote from: SArepairman on April 22, 2014, 05:03:51 pmThere are solutions, but not sure on pricing (thinking in terms of a whole house voltage stabilizer).

author: XOIIO
author_rank: Super Contributor
timestamp: April 22, 2014, 05:59:40 pm
content: Nothing catastrophic for some time, but I did just fry my multimeter a few days ago, can't afford a new one, and it happened right when I got bored with gaming and am in the mood to do electronics stuff again, probably a dozen times at least now I'm like "het that would be a good project" then realize I need a multimeter

author: SeanB
author_rank: Super Contributor
timestamp: April 22, 2014, 06:21:30 pm
content: You can buy distribution board whole house surge arrestors, they are quite common on farms where the supply comes in via a very ling overhead line. You have a lightning arrestor on the pole outside before the meter, and a unit in the distribution board that will trip the main breaker if a big surge hits it.Today I had a speed controller go bang on me on my mini lathe. So far whet I see is blown is a toroidal EMI filter ( it shorted out to a power resistor next to it), 2 1N5403 diodes, 2 BT152 thyristors, one charred beyong recognition resistor, one slightly cooked 47k 1W resistor ( it got the pulse, but unfortunately the side that contacted was the low voltage side, not the mains side), one very short SMD transistor ( marked 2A), one LM324 short between pins, and as yet other damage. Do think I will have to look for a new one on eBay instead of fixing it, or just make up a new one using a light dimmer and a bridge rectifier instead.

author: electronics man
author_rank: Frequent Contributor
timestamp: April 22, 2014, 06:35:56 pm
content: i realy stupidly solderd an electrolytic ( unvented i belive) backwerds into a power supply i was building (not high voltage mabe 30V at tops) and it blew up with one hell of a bang, lukily i was holding the board at an angle away from me, so the table took the blast not me. after this i kept finding pices of capacitor acrss my lab.

author: sacherjj
author_rank: Frequent Contributor
timestamp: April 22, 2014, 07:24:31 pm
content: Previous owners installed some 8 feet T40 Incandescent fixtures in the garage. They were old and not working really well. I assumed the ballasts were toast. I unplugged them and converted back to a bulb very soon after moving in, instead of the bulb to outlet adapter that the yahoo had decided to install them with. (At about 2x the amperage as the fixture was supposed to handle.) I didn't realize how good of a choice this was until removing them a few years later.They had been installed directly to the ceiling sheet-rock with no gap for ventilation. The ceiling was scorched where they had been and the ballasts had leaked some nice dark sticky substance. The sheet rock did its job and kept the wood ceiling joists from heating up to catch fire. Scary.

author: XOIIO
author_rank: Super Contributor
timestamp: April 22, 2014, 08:11:43 pm
content: Quote from: sacherjj on April 22, 2014, 07:24:31 pmHoly shit, no kidding that's scary.

author: SeanB
author_rank: Super Contributor
timestamp: April 22, 2014, 08:30:56 pm
content: They probably were killed by somebody relamping with the wrong lamps, if they were 8 foot then they probably originally had 200W powergroove lamps inside, and when they died they were replaced with a 60W regular 8 foot lamp. How often do you see a yard light with a 100W or 150W lamp in there instead of the correct 100W mercury vapour lamp, or the 35W HPS lamp.

author: kolbep
author_rank: Frequent Contributor
timestamp: April 22, 2014, 08:33:39 pm
content: Quote from: electronics man on April 22, 2014, 06:35:56 pmJust the other day I had several 470uF 16v Caps turn into flying shrapnel (one zooming right past my eye).The other few turned into mini smoke machines.Not to mention all the Small Switch Mode 5v to 3.3v regulators cracking in half.The Lesson is :1) Do not use a Fully Charged 12v Alarm Battery to power a CCTV DVR Under Test (Get / Build a Low Current Powersupply)!!!2) If the DVR Does absolutely nothing, DO NOT ASSUME that you have connected the supply the wrong way around the first time.3) 'cos when you swap it around, to see if that was your mistake, DUCK!!!!4) Cheap Chinese DVR's do not have decent input protection.5) Don't be impatient, Relax and Take your time. Check Supply Polarity before switching on (by looking at the way the Caps are polarised)At Least I had the Hard Drive unplugged!!

author: GreyWoolfe
author_rank: Unknown
timestamp: April 23, 2014, 03:31:20 am
content: I love the smell of blown capacitors in the morning. Not my wife, just me.

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 23, 2014, 04:29:17 am
content: Ah the wonders of eye protection. I only typically don eye protection (and ear protection if I never operated it before) when I am working with mains voltage circuits... I never realized that low voltage low capacitor capacitors could go off with such prejudice. I only ever saw them vent smoke.

author: calexanian
author_rank: Super Contributor
timestamp: April 23, 2014, 05:55:39 am
content: Nothing at home recently, but at work we had a prototype we were working on and had stuck a 9 volt battery on it so we could power it up without an external power supply (12VAC) everything on the board logic and display wise ran at 3.3V so everything was happy.. Until..... One of the other guys forgot to unplug the battery and pluged in the power supply putting 12VAC across a 9 volt lithium battery... Flames shot out.... He tossed the flaming wreckage of a battery still attached to the board off his desk and out into the carpeted hallway. The bosses office is at the end of said hall and his chair is right there in LOS, so all he saw was this flaming board being tossed out an office door! Then it got tossed out into the parking lot, still ablaze! The shop and a unique (toxic) smell for a little while after that. There is a scorched swoosh about 6 inches long on the hallway floor where the "Flamethrower" landed. Excitement! Obviously that was not a failure in the traditional sense of product failure, but it was still pretty catastrophic!