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

[QUOTE=Mudbone;37987901]Not always. cd and dvd drives have can be opened and fixed with some minor adjustments. I have also seen some people fix broken connection's on gfx cards.[/QUOTE] A friend of my brother sometimes literally boils the soldering off destroyed graphics cards and then hand-solders them back to working condition.

[QUOTE=Xenocidebot;37987591]No one has ever made a disposable camera "taser", and the coilgun requires a box of cameras, not one. Methinks you've been reading too much of the anarchist's cookbook. A disposable camera stun weapon doesn't stun. Nothing in a single disposable camera is sharp enough to penetrate skin and hit the fat or muscle layers, the voltage isn't high enough to negate that, and a taser operates via continuous AC pulses, not a momentary DC discharge. An incapacitating shock requires continuous DC discharge or an AC discharge into the muscle layer, not the instantaneous spike and falloff of a capacitor (or the even shorter pop if using the flash circuit). Extremely short shocks have no guarantee of even affecting a person, which is why all stun weapons are based on continuous current. They're not [I]that[/I] dangerous, you just got unlucky.[/QUOTE] Larger capacitors do provide continuous current for quite some time, enough to kill or at least hurt like fuck, I once shocked myself with cap charged to 350V at 100uF, it barely dropped 50V after giving me a very nasty shock. A 1 second shock is more than enough to stop the heart beating correctly although the risk is significantly less with DC compared to AC there is still a portion of the heartbeat where the heart is vulnerable to any interruption. see: commotio cordis.

[QUOTE=Mudbone;37985434]In the industry PSU's are field replaceable units. Meaning if they break we don't even try to mess with them. Just buy a new one and move on.[/QUOTE] In the industry you also don't have to worry about affording the new one and you don't have time to dick around with the old one. Bit different from my broke ass trying to keep the only stuff I can afford, IE what I have now, functioning. As a result I pop the cover off my PSU once every six months or so and thoroughly clean it to keep dust building up and overheating something to failure. I've also replaced the fan twice since I got it. Of course I drain the caps first. I'm not a retard so I educated myself on what's inside them and how to make them safe to work on before I ever popped the lid off of one. [QUOTE=sparky28000;37984132]I did that on a disposable camera's capacitor once shit gives amazing sparks.[/QUOTE] Try starting your car with one of those. I actually melted the tip off the end of one of those things jumping a starter solenoid one day. Rather scary what 500 amps will do... [QUOTE=Smug Bastard;37983172]Still, why the fuck would you ever try to take a power supply apart? That's absurd.[/QUOTE] ......to fix it? To scavenge cooling fans and heatsinks? To replace a bad fan? To clean it out and maintain it in good working order? Plenty of legit reasons to crack one open. The only reason I can think of against it is to maintain the warranty, and that's only good for a year or two if you buy it brand new. It is not difficult to safely work on a power supply if you educate yourself a little first. [QUOTE=SEKCobra;37981027]Opening a PSU is retarded, especially if you don't know what you are doing. There are 5 whole worlds between sticking some RAM in and servicing electrical devices. [/QUOTE] It's only retarded if you're retarded. It isn't hard to figure out what parts you need to be careful with and discharge in order to open them up safely. Five minutes of googling will show you A: What the caps are, B: what they look like, and C: how to discharge them without baking yourself. I hate it when people are told "Don't fix it, chuck it or pay someone else to." We should be saying "Yes, fix it, but educate yourself first. Learn how it works, learn how to service it safely, and save yourself a metric fuckton of money." This "Throw-away" "No user-serviceable parts inside" society frustrates the fuck out of me. Maybe it's because I grew up in a household that ignores the "Don't fix this" stickers and fixes things, maybe it's because my personality doesn't like relying on others to do shit I'm perfectly capable of doing, but I just can not stand this mentality. It's wasteful, both in resources and in money, and I'd love nothing more than to see society pick their spanners up and repair their own stuff once in a while. They'd save a fortune, they'd save Johnny Polar Bear, and they'd have a sense of self-satisfaction every time they use what they fix, knowing that they fixed it. Win Win fucking Win IMO. [QUOTE=TheTalon;37980665]That sounds like it could possibly fry the Motherboard. I wouldn't know for I haven't tried[/QUOTE] If you've ever been shut off by an AC failure you've done that inadvertently.

[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. [B]In perspect this means the kid touched a capacitor that likely discharged more than 20 amps through his body.[/B][/QUOTE] Where did you even get that number? That cap would have to be charged with tens of thousands of volts to dump 20 amps through him. He probably got around 100mA or so, enough for fibrillation.

As precaution make sure the power supply is totally plugged out, and hit the power switch on your PC a few times. Cheaping out on a PSU is the worst possible decision you can make when it comes to components. Make sure the PSU has a good power/quality rating.

[QUOTE=FlubberNugget;37988312]As precaution make sure the power supply is totally plugged out, and hit the power switch on your PC a few times. Cheaping out on a PSU is the worst possible decision you can make when it comes to components. Make sure the PSU has a good power/quality rating.[/QUOTE] Make sure you don't fucking touch insides of a PSU be it a cheap one or a premium one.

Case in point, you shouldn't even consider opening anything electronic unless you know what you are fucking doing.

[QUOTE=FlubberNugget;37988312]Cheaping out on a PSU is the worst possible decision you can make when it comes to components. Make sure the PSU has a good power/quality rating.[/QUOTE] This is a bit of a misconception, I've seen expensive power supplies with marginal design quality although they may use good components and cheap supplies that are well designed but with poor components. Best thing to do is assume whoever designed it is an idiot and none of the safety features (I.E bleed resistor) are working.

I've torn apart countless PSUs. Even been zapped twice...and yet here I am

[QUOTE=dass;37978982]Do they mean "disconnect the PSU" or actually "disassemble the PSU itself"? Like, opening it up and starting to remove parts from the inside? If its the latter, then all is explained. Kid had to be an idiot. Even actual professionals are scared shitless of messing with the interior of PSUs.[/QUOTE] Dunno where I fit into those categories then. I've taken apart numerous PSUs and even CRTs without discharging any of them first. I'm just super-meticulous about touching ANYTHING inside of them. In my career field (HVAC) it's common practice to discharge the capacitors we work with using screw-drivers (run capacitors especially, most start capacitors have a built-in "bleeder" resistor installed from the factory) before handling them. My instructor in college actually recommended Craftsman screw-drivers for this, as you can just walk in and get them replaced for free (once they said to him "I'm not supposed to ask you this, but what ARE you doing to these things?" to which he replied "You're right, you're not supposed to ask. :v:") Another amusing thing to note, the company I work with is actually refusing to sell Carrier's latest Green technology models because the compressors use DC compressors, and they contain capacitors that store 1-2000 uF at 300-450VDC, the owners/lead salesman believe them to be death-traps because of this. Somewhat hypocritical, as I recently salvaged from our scrap-yard one of their old 3-phase speed controls and it contains not one, but TWO 1100uF 400VDC capacitors inside.

I tried Opening a PSU once, I never knew how lethal it was till now. I was shocked by it too, guess I should be lucky to be alive.

[QUOTE=No_Excuses;37988252]Where did you even get that number? That cap would have to be charged with tens of thousands of volts to dump 20 amps through him. He probably got around 100mA or so, enough for fibrillation.[/QUOTE] Just want to add a little bit to this, 6mA on the heart is deadly, but the human body isn't that good of a conductor, so 6mA on your fingers won't usually kill you. Have an image that puts it into scale [img]http://www.physics.ohio-state.edu/~p616/safety/fatal_current.gif[/img]

[QUOTE=Goz3rr;37993194]Just want to add a little bit to this, 6mA on the heart is deadly, but the human body isn't that good of a conductor, so 6mA on your fingers won't usually kill you. Have an image that puts it into scale [img]http://www.physics.ohio-state.edu/~p616/safety/fatal_current.gif[/img][/QUOTE] wait so if you get over 0.2 you will survive if given CPR and burn treatment, if you get blow 0.1 you'll survive with some trouble, but anything between 0.1 and 0.2 and you're buggered?

[QUOTE=meppers;37979123]Its called natural selection[/QUOTE] Then why are [I]You[/I] still alive?

[QUOTE=Maloof?;37993929]wait so if you get over 0.2 you will survive if given CPR and burn treatment, if you get blow 0.1 you'll survive with some trouble, but anything between 0.1 and 0.2 and you're buggered?[/QUOTE] Probably a indication that you are already death at that point forward just a bit more crisp.

[QUOTE=Maloof?;37993929]wait so if you get over 0.2 you will survive if given CPR and burn treatment, if you get blow 0.1 you'll survive with some trouble, but anything between 0.1 and 0.2 and you're buggered?[/QUOTE] Yeah, 100-200mA fucks your heart's rhythm up, over 200mA and it's able to recover some of the time, I don't know what that is though.

I was a volunteer for a summer science camp. On the first day people were supposed to bring in stuff to take apart. I'm glad no one got socked because a lot of people took apart computers. One kid completely cut up a PSU. One person took apart an old crt tv too. There was no instruction to hold the power buttons to discharge the capactors, but this could have turned out really bad.

[QUOTE=gav618;37994478]I was a volunteer for a summer science camp. On the first day people were supposed to bring in stuff to take apart. I'm glad no one got socked because a lot of people took apart computers. One kid completely cut up a PSU. One person took apart an old crt tv too. There was no instruction to hold the power buttons to discharge the capactors, but this could have turned out really bad.[/QUOTE] they probably discharged in transit

R.I.P Brave soulja o7

A few years ago i disassembled an old PSU and the worst thing i got was a gigantic cloud of dust. Luckily i didn't touch any circuit stuff with my fingers, i used a brush and canned air. Still, i won't touch those cheap pieces of shit anymore, better invest in something at least decent :v:

My old tutor knew a guy when he lived back in Nigeria who killed himself trying to open one. Im quite suprised how many replies I'm seeing of people actually taking these things apart, they're just not worth it.

[QUOTE=P1X3L N1NJA;37994960]Im quite suprised how many replies I'm seeing of people actually taking these things apart, they're just not worth it.[/QUOTE] It's not particularly difficult to repair ATX supplies, the problem usually is quite obvious and 90% of the time is due to bad capacitor(s) rather than anything else. Also some people here like myself are actually electrical engineers or at least know what they're doing. Electricity is perfectly safe as long as your know how to work around it.

When I was quite young and first learning about the components of a computer I took apart a spare PSU and started fiddling around at it's insides. Haven't realised until quite recently how lucky I got.

[QUOTE=Rents;37994444]Yeah, 100-200mA fucks your heart's rhythm up, over 200mA and it's able to recover some of the time, I don't know what that is though.[/QUOTE] shocks that severe tend to stop the heart completely, rather than mess up it's rythym, so If you get quick medical attention, you're more likely to survive than if you experienced Ventricular fibrilation from a lesser shock.

[QUOTE=Chryseus;37988013]Larger capacitors do provide continuous current for quite some time[/QUOTE] What are you smoking? It's called a [I]transient[/I] for a reason. Your skin has a resistance between 300 to 10,000 ohms, and your fat 2,500 ohms, making a roundabout circuit to the muscle layer between 5.6kohms (moist) to 25kohms (dry). A 350V cap is only going to hit you with 62.5mA to 14mA at 0 seconds. Both will hit below the threshold of pain in seconds. You need 100mA or more, for more than an instant, to kill anyone without a heart condition, and 10-20mA for around 5 to 7 seconds of drop someone with a DC electrical weapon. In either instance within 3 seconds the current of your cap will be below the pain level, bordering on lack of sensation. People often vastly overestimate the pain they've experience via electrical means because it's rare. In your case you could only have been at a current capable of giving you a "very nasty shock" for about the amount of time it takes the average person to realize they're in pain.

People aren't often shocked, and it's a completely different type of pain from most types of sudden shocks. And because of that it can be very painful and/or scary. Best thing to do is to rush to a cold tap and get the contacted area under it.

[QUOTE=proch;37993936]Then why are [I]You[/I] still alive?[/QUOTE] It's called luck :v:

[QUOTE=Xenocidebot;38000964]What are you smoking? It's called a [I]transient[/I] for a reason. Your skin has a resistance between 300 to 10,000 ohms, and your fat 2,500 ohms, making a roundabout circuit to the muscle layer between 5.6kohms (moist) to 25kohms (dry). A 350V cap is only going to hit you with 62.5mA to 14mA at 0 seconds. Both will hit below the threshold of pain in seconds. You need 100mA or more, for more than an instant, to kill anyone without a heart condition, and 10-20mA for around 5 to 7 seconds of drop someone with a DC electrical weapon. In either instance within 3 seconds the current of your cap will be below the pain level, bordering on lack of sensation. People often vastly overestimate the pain they've experience via electrical means because it's rare. In your case you could only have been at a current capable of giving you a "very nasty shock" for about the amount of time it takes the average person to realize they're in pain.[/QUOTE] Around 20mA through the heart is the threshold for ventricular fibrillation (less for AC), as for time 1 second is more than enough, you only need to interrupt the cardiac cycle for a very brief time to upset the rhythm, the reason devices such as tasers are not usually lethal is because the conductors are close together, lethal shocks are nearly always caused from arm to arm or lesser arm to leg shocks. Capacitors [b]store[/b] charge this takes [b]time[/b] to discharge so no it's not a transient event unless your practically shorting it out, the actual discharge time can be calculated using simple RC time constants, one RC constant when discharging is equivalent to a drop in voltage of 37%, assuming 350V one RC constant will equal 221V. Assuming my body resistance is 10k and a 100uF cap that will give a peak current of 35mA, after one time constant which is (T = RC) 1 second the current will be 22.1mA. I've experienced both AC and DC shocks numerous times so I can assure you I can fully tell when I am being shocked, and I did actually measure that cap after it shocked me, it was around 170V definitely not a transient event. Oh and don't even try to go into detail when it comes to body resistance, it can vary dramatically depending on many variables, once your being shocked and the skin is breached it can drop significantly making things much worse.

[QUOTE=Killuah;37981797]How do you do it directly?[/QUOTE] ???

Just recently handled a socket adapter while it was plugged in. It malfunctioned in my hands and literally exploded like a white firework sparkler on Independence Day with a loud bang. Dangerous electrical shocks are actually pretty scary especially when it can also come down to everyday household items.