16-year-old killed by unplugged PSU while fixing family PC - Polidicks

The most stupid thing I've ever done was play around with a CRT monitor while it was plugged in, the anode had come lose and the tube had lost the vacuum, so I reconnected the anode while it was powered to see if it still worked (It did). I knew what I was doing but looking back I'm still amazed I was that stupid, even when I pulled a PSU apart I took more precautions.

[QUOTE=GreenDolphin;37980447]Some interesting facts. 10 milliamps can produce a painful shock. The closer you reach 100 milliamps the closer you run the risk of completely ceasing to breath and going into [url=http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004467/]ventricular fibrillation[/url]. 100 milliamps and above is incredibly lethal. Same as before but your heart will definitely go into VF (ventricular fibrillation). You will die within minutes unless you receive immediate medical attention. 200 milliamps and above your muscular contractions will be so severe that your heart will forcibly clamp, thus, saving you from VF. You will be unconscious, have severe burns and will definitely stop breathing. In this stage you will actually have a much higher chance of survival if you receive immediate medical attention and get resuscitated. In perspect this means the kid touched a capacitor that likely discharged more than 20 amps through his body.[/QUOTE] In that case, I feel terrible for whoever found him.

Poor kid, I'm starting to think I was lucky when a PSU gave me a slight jolt before I threw it across the table

I get scared at the thought of someone putting their hands inside a PSU without knowing much about electronics. Not even messing with the most venomous spiders in the world is as dangerous.

[QUOTE=latin_geek;37979060]there's also these but they aren't orange and have exclamation marks and frickin' lightning bolts [IMG]http://img.tomshardware.com/us/2006/05/29/from_treasures_to_trash/blackwidow-psu2.jpg[/IMG] watch as someone wants to change the design to [IMG]http://puu.sh/1dcGT[/IMG][/QUOTE] how can u get electrocuted, if it's unplugged?

[QUOTE=Barbarian887;37981269]what the fuck is that?[/QUOTE] Something you don't want. [url]http://en.wikipedia.org/wiki/Compact_Disc_shattering[/url] [editline]10th October 2012[/editline] [QUOTE=Wolfz;37981591]how can u get electrocuted, if it's unplugged?[/QUOTE] Ever unplugged a laptop charger and have seen the LED still burn?

[QUOTE=Wolfz;37981591]how can u get electrocuted, if it's unplugged?[/QUOTE] It still holds a charge. A lot of electrical appliances still have their charge after being unplugged.

[QUOTE=Del91;37980125]I literally take apart and put together computers everyday at work. It takes like 5 seconds for the capacitors to discharge. We also dismantle CRT tvs and monitors, LCD screens, projection tvs, servers, etc etc. How do you do it directly? I got a free 590gtx though so it's cool. [editline]9th October 2012[/editline] That's another way to discharge it. Push the power button with it unplugged and it'll suck all the juice out.[/QUOTE] How do you do it directly?

I'm not exactly a certified serviceman, but i know enough about electronics that plenty of stuff is dangerous even when not plugged in, i usually leave a PSU for 3 days without power before even attempting to open and, and then still be careful. Usually i scramble parts from them for other projects (temperature sensors are usually separate circuits, easy to use), or if i need another fan. They also make a nice alternative to really expensive lab power supplies. I did manage to shock myself on a toaster once though, when my bread got stuck i tried to get it out with my knife and shorting the thing :v:

[QUOTE=koeniginator;37979006]well technically it doesn't say anything about it being dangerous it just says it's pointless to open[/QUOTE] I think that exclamation mark and the lightening bolt are really clearly a warning.

Just discharge the capacitors or wait 2 minutes before opening it. Voilá, no more stored energy...

[QUOTE=Goz3rr;37982099]I'm not exactly a certified serviceman, but i know enough about electronics that plenty of stuff is dangerous even when not plugged in, i usually leave a PSU for 3 days without power before even attempting to open and, and then still be careful. Usually i scramble parts from them for other projects (temperature sensors are usually separate circuits, easy to use), or if i need another fan. They also make a nice alternative to really expensive lab power supplies. I did manage to shock myself on a toaster once though, when my bread got stuck i tried to get it out with my knife and shorting the thing :v:[/QUOTE] I do the toaster thing too, except I use wooden fork that I made once.

Must be a poorly designed power supply, any decent one is designed to slowly discharge the capacitor. Still anyone with a basic understanding of electronics knows to make sure large high voltage capacitors are discharged before touching, although it's rather unusual that he died touching one, just bad luck really.

Too be fair, I have never seen a psu saying "May pose shocking hazard even when unplugged" or similar. If you dont know much, it's easy to assume its safe if its unplugged.

The first computer I owned had a PSU that became clogged as hell with dust and I didn't have the cash to replace it. My sphincter had the diameter of a hydrogen atom the whole time I was blowing dust out of its fan. After I removed the casing from it. And after I discharged the terminals.

I took apart a 500W PSU ~2 years ago to replace a broken fan inside of it. I waited 1 hour after unplugging it. I wonder how long the capacitors hold the charge for? Also, how to properly discharge them without killing myself?

When working on PSUs always ALWAYS short the filter caps and any other large caps.

[QUOTE=Barbarian887;37981269]what the fuck is that?[/QUOTE] A nerdy fragmentation grenade. [editline]10th October 2012[/editline] [QUOTE=Unsmart;37982423]I took apart a 500W PSU ~2 years ago to replace a broken fan inside of it. I waited 1 hour after unplugging it. I wonder how long the capacitors hold the charge for? Also, how to properly discharge them without killing myself?[/QUOTE] With a shitty capacitor? I'd say around 5 hours average, medium could be anywhere between a day and a week, high end could be up to a month. But this is why you always fucking discharge shit before poking it.

[QUOTE=16bit;37978836]He took apart the PSU.[/QUOTE] That explains it, never do this unless you're trained to do so and are in an appropriate environment with the equipment to discharge them.

[img]http://i.imgur.com/is0ph.png[/img]

I've fixed my old power supply once, installed some higher quality caps to replace the wrecked ones, still, i always discharged the caps before doing anything, and you don't get buzzed if you touch the cap itself only if you touch the terminals on the back of the pcb If you pick up the PSU PCB by it's behind you deserve every amp you're getting through your heart for not reading the fucking DANGEROUS sticker

Since I had to do studies in the more "electrical" parts of IT, I can safely say You never, ever, EVER try to MODIFY ANYTHING that can carry an electrical charge - without knowing what the hell you're doing I shocked myself hard when I had to construct a two-way switch system to operate light bulbs in a living room environment, got my finger stuck inside a wire that was then accidentally connected to the 240V outlet, 5 seconds of pure hell

I used to mess around with crt screens allot when i was a kid. Only recently i figured out how lethal that was, i'm glad to be alive. Then i learned to be careful when i got shocked 3 times by a capacitor from a camera. I often wear these now: [IMG]http://judaismandmedicine.files.wordpress.com/2010/02/ist2_158385-rubber-gloves.jpg[/IMG] I know that they don't conduct by eeuhm testing them out....

That's a horrible way to die and I feel a lot of sympathy for his family. Still, why the fuck would you ever try to take a power supply apart? That's absurd.

[QUOTE=0lenny0;37983126]I used to mess around with crt screens allot when i was a kid. Only recently i figured out how lethal that was, i'm glad to be alive. Then i learned to be careful when i got shocked 3 times by a capacitor from a camera. [/QUOTE] Ah man disposable cameras are the worst, in case someone hasn't had the pleasure of knowing one in person, [IMG]http://web.mit.edu/hchin/Public/activlab/images/d-camera2.jpg[/IMG] You see that big cylindery thing? That's a capacitor for the flash, it turns the measly 1.5v in a AA battery to a really short 300v discharge. That's 3 times a US wall socket, and it give you a fucking nasty burn if you fuck around inside a disposable camera and touch the terminals. I've done it once or twice and could barely move my fingers for a good 10 minutes after it. Now this is where it gets scary, though. Here's a look at a computer PSU: [IMG]http://www.webx.dk/oz2cpu/pcmod/psu-pc400-comp1.jpg[/IMG] That's [I]several times[/I] the capacitors, including the massive ones on the left, some of them going up to 500-600v, and they store more energy, meaning the shock is harder, longer and perfectly capable of killing you. Even if you don't touch the leads and, say, work on the other end of the PSU, the capacitors are still connected to various components via the PCB, so there's a pretty high risk of getting shocked if you touch anything inside a PSU.

which part of the capacitor would you have to touch to get a shock? the exposed metal top? or just any part of it?

I... once as a kid, COMPLETELY stripped down a PSU. Holy shit, I had so much luck.

[QUOTE=apurplerock;37983356]which part of the capacitor would you have to touch to get a shock? the exposed metal top? or just any part of it?[/QUOTE] Touching the solder leads under the capacitor, or anything connected to them. I'm glad I found out about the dangers of capacitors long ago. I have an old vacuum tube Hammond organ which has MASSIVE power supply caps. And tube power supplies are 10x scarier than PSU's.

I've been shocked four times in my life. Two times by outlets, two times by flash capacitors. Luckily the two cameras were just small, cheap ones. I imagine a DSLR flash is bit more brutal :v:

[QUOTE=JustExtreme;37982594]That explains it, never do this unless you're trained to do so and are in an appropriate environment with the [b]equipment to discharge them[/b].[/QUOTE] [img]http://www.neon-dreams.org.uk/gallery_image/image/13/medium/screwdriver.jpg[/img] Real men use one of these. [quote]That's [I]several times[/I] the capacitors, including the massive ones on the left, some of them going up to 500-600v, and they store more energy, meaning the shock is harder, longer and perfectly capable of killing you.[/quote] Those ones on the left are on the secondary side which is low voltage, so the actual value of capacitance means very little, at worst you might burn yourself if you're wearing something metal. The only ones you need to be careful of are the big filter caps on the right side. Never touch the caps until you are 110% sure they are discharged by shorting the the terminals, do this more than once as they can and do recharge slightly. Also in most caps the top vent if metal is connected to the - side, I've shocked myself before making this mistake. TV's need to be discharged under the high voltage anode cap, look on youtube plenty of videos. Never ever touch microwave ovens unless your a professional, and even then...