Electically live things you don't expect - OW!

Electically live things you don\'t expect - OW!

Well, not big ouch, but sore enough to make me recoil my hand and nearly fall off the bed. In this case the metal surround on the headphone and mic jacks on my laptop. Going to remember that in future.

Anyone else encountered something like this before?

Of course, this is an old machine - so there's every possibility that it's a fault, it's working though so I'm not going to mess with it, I can't afford to replace it!

Re: Electically live things you don\'t expect - OW!

Fix the problem. If there was enough electricity (not just a static electricity shock) for you to "OUCH" and pull away, then there is a problem.

Something is wrong. Fix it.

Re: Electically live things you don\'t expect - OW!

Well, not really enough to make me pull away - just enough to actually notice that there's something there. Certainly not as bad as what you'd get from touching a TV RF lead for example (heh, first time I encountered that was amusing - or so my father thought anyway when I just about knocked myself out on the bookcase).

The recoil in this case wasn't so much due to discomfort - just that I was totally not expecting that when flicking through a slideshow using the control key as the advance button!

Not really much I can do in the way of sorting (or investigating for that matter), it's obviously an internal issue with the system. The power supply's just +18V and ground. Somehow I doubt I'm going to see anything inside the case which I can work on. Laptops aren't the most user-serviceable of things.

Re: Electically live things you don\'t expect - OW!

One time I was ordinarily flipping on the lightswitch in my kitchen and my dad forgot to inform me that he did electrical work on that part of my house (usually a problem because he leaves things(even very dangerous things) unfinished); so, I was flipping on the light and something was not right because a got a 120volt shock that took me to the hospital. (No, my father isn't that stupid anymore /ubbthreads/images/graemlins/tongue.gif )

Anyway, it more scared me than hurt me because it was about 1 a.m., the rest of the house was dark, and I had watched the movie Signs just minutes before /ubbthreads/images/graemlins/mpr.gif

Anyway, I agree. That Laptop needs to be thrown away or fixed.

Re: Electically live things you don\'t expect - OW!

I was about 12yrs old and the rototiller didn't have a kill switch. My father said just pull the sparkplug cap when I was finished turning over the garden. After receiving a jolt on my failed attempt to shutdown, I tricked my younger brother into trying. He was shocked yet successful, and enslaved me into completeing his chores for next few days in trade for not telling on me.

Re: Electically live things you don\'t expect - OW!

The light switch above the head of my bed is rather old-fashioned; it has these two large buttons for on and off rather than a lever. I went to turn off the light a month or two ago, and got zapped on the metal switchplate surrounding the buttons. I measured it the next morning with a DMM and got a reading of approximately 4.5 volts.
In any case, I don't touch the switch directly anymore; I currently use an old shirt or the rubber end of my cane to operate the switch, because I rather dislike getting zapped.

Re: Electically live things you don\'t expect - OW!

...whatever you do, DON'T touch a TV screen while you are on a regular corded phone.
YEOWCH!

Re: Electically live things you don\'t expect - OW!

Shouldn't happen. If the Laptop has an outboard charger, the problem has to be associated with the inverter circuit that drives the cold cathode fluoros that light up the screen. Otherwise the highest voltage you are likely to see is about 20v that some chargers provide. Everything else inside the laptop runs at no more than battery voltage. The inverter output will definitely get your attention however. Usually on the order of 300-700volts.

Re: Electically live things you don\'t expect - OW!

[ QUOTE ]
AlphaTea said:
...whatever you do, DON'T touch a TV screen while you are on a regular corded phone.
YEOWCH!

[/ QUOTE ]

Because I'm an idiot, I'm going to try that /ubbthreads/images/graemlins/grin.gif

Re: Electically live things you don\'t expect - OW!

That which doesn't kill us is called "A learning experience"!!

Back in the day of un-grounded plugs and such, I got wacked by many pressure washers, some metal body electric tools etc.

I learned to HATE a service call where the maching was shocking!!!

Been a long time since I got hit though. I did burn a Klein screwdriver nearly in two a couple years ago...

I didn't feel a thing!

Re: Electically live things you don\'t expect - OW!

Mmmh...
Oddly enough, I have a 8 years old laptop that shocks me when I touch the side for more than 20 minutes. It seems to be a bit random but I get shocked everytime; it's not very painful though.

Re: Electically live things you don\'t expect - OW!

There IS a quirky thing about headphones/speakers...

If a speaker coil is energized with DC, and then suddenly DE-energized, the collapsing magnetic field in the coil produces a spike that could be a couple hundred volts. You can actually prove this with a 9-volt battery, some bare speaker wires and a neon lamp.

* Disconnect the speaker wires from everything else
* Connect the neon lamp in parallel acropss the speaker wires
* With gloves on, touch the speaker wires to a 9-volt battery.
* Then REMOVE the wires from the battery while watching the neon lamp.
* Note the flash! And remember that it takes AT LEAST 60 volts to get the neon lamp to light!
/ubbthreads/images/graemlins/ooo.gif

Re: Electically live things you don\'t expect - OW!

It took my younger brother YEARS to figure out there was a better way to test spark on a lawn mower than sticking a screwdriver in the boot and touching the plug with your other finger. .

My dad has an old shop lamp that he loves, even though you can see the copper through the side of the cord. And no, he won't let me replace the cord, we just have to stand there and get that special tingly feeling when you touch it. Not quite a shock, but enough to notice. .

Re: Electically live things you don\'t expect - OW!

If it's just the remotely, might be called pain, and a buzzing then it's not that all unusual. Every laptop I've ever owned has done it from the metal components. Or in the case of this current laptop with an entirely metal case you can feel it anywhere. Only if you're grounded though. Right now it's plugged in on my desk and I feel nothing because there is no path through me to ground. But when i plug it in downstairs at the kitchen table, in my bare feet on the tile I can definitely feel it quite strongly sometimes.

I actually have 2 of these right next to each other, and sometimes touching both is actually painful /ubbthreads/images/graemlins/smile.gif

If thats all it is, then it's nothing. if it's actually painful then there may be something wrong after all.

Re: Electically live things you don\'t expect - OW!

[ QUOTE ]
BakerOnFire90 said:
[ QUOTE ]
AlphaTea said:
...whatever you do, DON'T touch a TV screen while you are on a regular corded phone.
YEOWCH!

[/ QUOTE ]

Because I'm an idiot, I'm going to try that /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]

Well?? How did this work out for you? Now I have to try it too.

Our old house had a problem with the fridge, if you touched the kitchen taps while holding the fridge door then you got the full load..

Re: Electically live things you don\'t expect - OW!

A buddy of mine tried to strip the insulation off both the red & green wires for a phone jack, at the same time, with his teeth. The fact that someone called (causing the normally low voltage wires to carry a ring voltage) while he was still biting the wires, though... /ubbthreads/images/graemlins/grin.gif

I, on the other hand, tried to find a bad spark plug wire on an old Chevy Blazer (back when there was enough room around an engine to actually sit in the engine bay with the motor) - while standing barefoot on the ground. The engine was missing, and I figured the easiest way to find the bad wire was to remove & replace each spark plug wire (with the engine running) until one didn't make a difference. Decided on a different method after trying one wire... and then Dad mentioned that you can't buy just one spark plug wire anyway. /ubbthreads/images/graemlins/blush.gif

- Dwayne

Re: Electically live things you don\'t expect - OW!

One time I pulled on a metal ballchain light switch that was malfuntioning, not turning on all the time. Well one time it shocked me. My whole neck and sholder cramped up and scared the sh*t out of me. Kinda burned too. Not long after that it was replaced.

Craig: sounds like that switch wiring is shorting to the plate. I'd get that fixed, as it could be a fire hazard.

Re: Electically live things you don\'t expect - OW!

I managed to lock myself out of my old '73 Civic (first year for them) with the motor running. I had popped the hood, so I figured no problem, just pull the coil wire. Took a nice zap since I was leaning on the body with my other hand. It was very enlightening. /ubbthreads/images/graemlins/ooo.gif

Re: Electically live things you don\'t expect - OW!

worst "zap"? Fully charged 300vdc .25 farad cap (NOT Microfards)

Son of a...... That HURT, and I was lucky I was not killed. I was thrown across the room - I probably was NOT killed because I was following the one hand rule, and ONLY got zap across the one hand

Work around electronics enough, and you get zaped - nature of the business - 110v didn't even raise eyebrows

One day, I'm working in the lab, and I'm leaning on this box hat has a variac in it, as I'm probing a low voltage board. Every once in a while, when I leaned on this one corner with the fleshy part of my arm, I'd feel what felt like a little burr on the corner. Took out a file, filed the corner to get rid of the burr, but still kept getting pinched - and ONLY when I leaned on the corner. Eventually I took out a meter and measured to ground - 97 volts.... Fixed the short from the variac's wiper to case, and stopped getting pinched

Every once in a while you'll run across electricians who check 110v circuts by putting their fingers across the leads

Re: Electically live things you don\'t expect - OW!

I've been bit by 48 VDC and 110V AC ringer voltage on telephone systems, 120 VAC mains, 240 VAC, 5000 VDC from a TV flyback, 12,500 VDC and 17,500 VDC from radar systems. Luckily the radar supplies were low current and did not kill me but I'll tell you they cleaned my clock. Got a few RF skin trace burns also. I listened to my instructors and took off all jewelry and kept my left hand in my pocket while working with high-voltage and it probably saved my life.

I knew a guy who grabbed the wrong thing on a Klystron. 10 KV went through his arm and torso and found it's way out of his butt into an oscilloscope he was standing next to. Put burn holes in his pants. His name was Rodney and boy did he get ticked after three weeks of "How ya doing lightning Rod?"

Newbies in my comm shop always got assigned to set up telepone connections over field wire from BD-5 cans (the cans had screw-down terminals for connection to underground telephone cables and then field wire was run to the termination point). A comm specialist sate in the truck with a radio and keyed up they mic while the wires were being stripped then someone from the main compaound would dial the live line... We only sent the real obnoxious people out to connect phones in the rain....