Archive for Tuesday, October 9, 2012

Shawnee teenager electrocuted while working on computers

October 9, 2012


A teenager recently found dead at his Shawnee home died of electrocution while working on computers, according to police and coroner reports.

The teenager, whose name is being withheld at the request of his family, was found lying unresponsive on his bedroom floor. “Near the body were partially dismantled computers on which he had been working,” an autopsy report states.

The boy’s father summoned emergency services and started resuscitation efforts, but the teen was pronounced dead at the scene.

The autopsy, performed by assistant Johnson County Coroner Dr. Michael Handler, “revealed an electrical burn on the left chest,” one of the forensic indicators of electrocution.

“That’s very rare,” Dan Besco of Besco Computers said of the accident. “I can’t believe it happened in Shawnee.”

Besco, whose computer repair business has been serving Shawnee since 1976, said the victim “had to have opened up the power supply” to sustain the lethal charge.

Capt. Dan Tennis of the Shawnee Police Department confirmed “it was a tower computer; he was stripping it out when he got into the power supply.”

According to Besco, he never opens computer power supplies, which typically bear “high voltage” warnings.

“I don’t go there,” he said of power supplies. “You can’t repair it. There are no serviceable components. It’s a $20 box, so if it’s not working, I take it out and put a new one in.

“The moral of the story is: Heed warning labels.”

Dave Bradshaw, a technician with Skyline Computer Service in Shawnee, said computer power supplies include capacitors that store electricity and can deliver a potentially lethal shock even when the power is shut off.


billybob1 3 years, 1 month ago

Recently? How about last August. Are you getting the news via the Pony Express?

Mike Frizzell 3 years, 1 month ago

Rob Roberts is the news editor for the Shawnee Dispatch, a World Company newspaper, which covered the story on October 3rd.

gccs14r 3 years, 1 month ago

The cooling fan is a serviceable part. Just don't be dumb while working inside.

Fred Whitehead Jr. 3 years, 1 month ago

I haave worked on all sorts of electrical and electronic gear for many of my 68 years. This includes restoring antique radios and musical instrument amplifiers, electronic musical instruments and older televisions (the kind with vacuum tubes.). I have made lots of smoke and sparks in my efforts, but always remain wary of any circuit that has been recently energised.

While I know that power supply capacitors (sometimes erroniously called "condensers") can store a brief amount of electric voltage and can cause you a nasty shock if you do not discharge them first, I am puzzled at just what sort of capacitors are in play here? The most injury I have seen from such a shock has been a physical injury to your body from the unexpected "bite" from the charged capacitors and recoiling your arm or hand causing a bodily injury.

y.I have been "bit" many times in spite of knowing these precautions, but suffered no ill effects except emptying my vocabulary of "military" invective.. I am just wondering if this unfortunate boy had other medical problems that would be affected by a very momentary shock from a charged capacitor? I have never heard of anyone dying from such an event unless the equipment was plugged in and energised from line voltage.

Something seems fishy here and perhaps no one knows what really did happen here,.

DillonBarnes 3 years, 1 month ago

Any chance he still had the unit plugged in?

Liberty275 3 years, 1 month ago

He could have had some underlying condition that when combined with the rather tame shock you generally run into in the home, had a more drastic effect.

Currahee 3 years, 1 month ago

All the parts are serviceable depending on how good your soldering skills are, which to most people are non-existant. But it is easier to just throw it away and get a new one if it's gone. The capacity of the biggest capacitor varies on the wattage of the power supply, but it's safe to say that this kid was incredibly unlucky and his heart may have stopped as a result of the shock. It's like getting hit with lighting, some people live and some people die. Just depends on how your heart handles it.

Condolences for the family. You don't want to mess with the bigger capacitors. Can be very dangerous...

friendlyjhawk 3 years, 1 month ago

What a sad thing to happen and all you posters can think about is how much YOU knew and what YOU did. Shame on you.

Ron Holzwarth 3 years, 1 month ago

I do not believe it is possible for a capacitor to give anyone a lethal shock. A shock, sure, but it will be of very brief duration, and that's it. Not fatal, no way.

If it is necessary to work with a charged capacitor, use a 1K to a 10K ohm resistor, and short out the leads with it. That's about the resistance of skin contact, it varies with how moist the skin is. The capacitor will be completely discharged very quickly, maybe a second. Oh gee whiz, blast from the past, compute this, keeping in mind the capacitor will be considered to be discharged after 6 time constants,,,

The power supplies used in computers are of the switching type, which is very different than the linear types that were used decades ago. Large capacitors are not used in the construction of switching power supplies.

What is fatal is this: 110 VAC passing through a person's chest. 60 Hertz is very close to a normal heartbeat, and electricity causes a contraction of the muscles it passes through. The rhythmic pulses of the electricity through the heart throw its rhythm out of whack almost instantly, and even if the electricity is stopped it will always be a close call about whether the person can be revived because almost instantly, the heart is in fibrillation and blood flow is completely stopped.

Breathing is often stopped as well, but that's not nearly as big of a problem of a heart in fibrillation. Because, you have almost 5 minutes to get the electricity off and begin resuscitation.

Electrical devices are certainly something that you should never play with unless you know what you are doing very, very well.

Liberty275 3 years, 1 month ago

I'd add, if you touch anything you are suspicious of, use the back of your hand first.

Ron Holzwarth 3 years, 1 month ago

Yup, yup, yup! This is a repeat of a posting I made on Sarah St. John's '100 Years Ago' column on August 10, 2012:

Yup, that amazing thing called electricity can sure get you!

Once I got caught on an electric fence, it's too lengthy to describe exactly how that happened, and I could not get out, my younger brother didn't know how to shut off the fence, he just ran into the house screaming about what was going on.

Then my Dad hollered at him, "Shut up! Can't you see I'm on the phone?"

My younger brother sat on the edge of his chair for a while, and the very second my Dad hung up the phone he screamed: "Ron's caught on the electric fence!"

Then my Dad came running out, and I was OK except for some bluish holes on my right leg.

Another time my Dad was trying to see if the electric fence was working, so he told me to hold his hand to see if we got shocked. We didn't get shocked, so then my Dad told me to take off my tennis shoe and stand on the ground, maybe that was why we weren't getting shocked.


And then years later, I was an EM attending BEEP school at NTC San Diego, and we were all assured that at least one of us was going to become a member of the 440 club. That meant that at least one of us was going to break some rule about the 440 VAC box and get shocked.

We didn't have a single member of the 440 club in my class. Because I was the second member!

Liberty275 3 years, 1 month ago

" we were all assured that at least one of us was going to become a member of the 440 club"

I'm a member of the 40,000 volt club thanks to an MSD coil and a leaking plug wire on the vette.

cabocrazed 3 years, 1 month ago

I wonder, despite being unplugged from the wall, if the computer was still plugged into a UPS?

jayhawklawrence 3 years, 1 month ago

Listen people. It only takes 40 to 50 milliamps to kill you. Some of these capacitors carry 20,000 volts and for a 3 phase motor (example) some of these can hold a charge for a couple of days or more.

Obviously, the amp level was enough to kill because what kills you is when you create a circuit through your heart which means both hands were touching something so that a circuit was created through the heart. That is why they tell you to never put both hands into an electrical cabinet at the same time. I am talking about a low amp level here. Obviously enough amps can fry you.

This was a very tragic and unusual accident and very sad but from the responses here on this blog it is obvious that people need to review electrical safety procedures.

gphawk89 3 years, 1 month ago

"electrical burn on the left chest..." I really can't imagine any capacitor in a modern PC power supply having enough energy to do that. Sure there are capacitors that could kill a person, but not the kind in a PC. Hate to say it, but I too wonder if he simply had the PC plugged into the wall. Dumb mistake, but I'll bet most folks that work with electronics for a living have done that at least once.

And there are plenty of serviceable components in a power supply. Like Currahee said, they all are if you know what you're doing. Yeah it's easier to replace the supply, but most supplies are not "$20". Some are $200 or more.

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