# very strange problem - slight electric shock from USB ports?



## speedy11131 (Jan 3, 2010)

I have a laptop that for some reason sends a small shock current when I either touch the port by accident, or touch the connectors on a cable or anything connected to it at the time (for example, ipod cable connected to USB port will shock me if i touch the ipod)

And it's not even a shock, it feels more like the current is running through to my fingers, a sort of tingling feeling.

It's very odd because it never did this before. Is this some sort of electric isolation problem? Is it something I can fix or have to send to repair somewhere?

It's a very small shock, I'm assuming because USB is only rated at 5V?

It is an HP laptop, don't have the model number off the top of my head.


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## pbmaster (Jan 3, 2010)

Sounds like a very important piece of hardware is going to get shorted out soon.


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## BUCK NASTY (Jan 3, 2010)

speedy11131 said:


> I have a laptop that for some reason sends a small shock current when I either touch the port by accident, or touch the connectors on a cable or anything connected to it at the time (for example, ipod cable connected to USB port will shock me if i touch the ipod)
> 
> It's very odd because it never did this before. Is this some sort of electric isolation problem? Is it something I can fix or have to send to repair somewhere?
> 
> It's a very small shock, I'm assuming because USB is only rated at 5V?



If you can feel it, it's more than 5v.


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## Solaris17 (Jan 3, 2010)

time for a rebuild if its in warrentee get it sent back if its not rebuild it then try the store if it doesnt work.


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## Goodman (Jan 3, 2010)

Got any carpet on the floor at your feet or near the computer?


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## DirectorC (Jan 3, 2010)

I think laptops are suffering from awful build quality problems.  My nephew tried to plug the end of a plug from a headset into a USB port in my sister's laptop and the laptop shut down and it no longer works with the battery, she has to have it plugged into the wall.  That makes absolutely no sense whatsoever, it was just a headset plug that touched the metal of a USB port, WTF.


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## Fourstaff (Jan 3, 2010)

The last time I had electric shock from my hardware, the PSU died, taking quite a lot with it. I think it is time to try to get HP to honor their warranty (not that they will)


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## kurosagi01 (Jan 3, 2010)

DirectorC said:


> I think laptops are suffering from awful build quality problems.  My nephew tried to plug the end of a plug from a headset into a USB port in my sister's laptop and the laptop shut down and it no longer works with the battery, she has to have it plugged into the wall.  That makes absolutely no sense whatsoever, it was just a headset plug that touched the metal of a USB port, WTF.



the only laptop manufacture that has the worst and poorest build quality is ACER,you should NEVER buy an ACER even it is cheapest laptop out there and their customer service is terrible.

Well anyways is that laptop an ACER by any chance??


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## ste2425 (Jan 3, 2010)

speedy11131 said:


> It is an HP laptop, don't have the model number off the top of my head.


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## Fourstaff (Jan 3, 2010)

kurosagi01 said:


> the only laptop manufacture that has the worst and poorest build quality is ACER,you should NEVER buy an ACER even it is cheapest laptop out there and their customer service is terrible.
> 
> Well anyways is that laptop an ACER by any chance??



Its HP according to first post. HP is not much better the way they handled the dead gfx card problem.

Edit: Ste beat me


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## kurosagi01 (Jan 3, 2010)

ah i see,well i guess most laptops have issues these days,but hey HP customer service is indeed better than ACER.


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## Mussels (Jan 3, 2010)

its not voltage that you feel, its the amperage - and USB gives just enough to feel without being able to cause harm.


the parts of the port accesible from the outside (that metal frame that surrounds it) SHOULD be earth/ground.

Its possible somethings up with the laptops power brick, or maybe with the mains power there - does the problem occur when running on battery only, with NO external devices connected? (no mice, no PCMCIA cards, no cardbus, no memory cards in the card reader, etc)


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## exodusprime1337 (Jan 3, 2010)

you aren'tusing wone of those 3 pin to 2 pin power cord adaptors commonly found in old houses with dated electrical systems are you?? i have a few power outlets around he house and if i use the adapator and plug a 3 pin item in i can feel the shock easily.


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## speedy11131 (Jan 3, 2010)

The model number is Pavillion dv9000

EDIT: just unplugged from power outlet and let run off the battery, don't feel the shock anymore.


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## @RaXxaa@ (Jan 3, 2010)

i had a major problem like that once in my pc and still have it only when i plug monitor into my psu... and its a metal case so its really a bad current flowing through me until my monitor short circuited.... any how it looks like maybe your Power adapter is not grounded. not an expert but check your power adapter


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## Mussels (Jan 4, 2010)

maq_paki said:


> i had a major problem like that once in my pc and still have it only when i plug monitor into my psu... and its a metal case so its really a bad current flowing through me until my monitor short circuited.... any how it looks like maybe your Power adapter is not grounded. not an expert but check your power adapter



i had that as well from a CRT monitor with bad earthing (monitor died next time it zapped me, and blew me clean across the room) - its why i asked him to do an isolation test


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## keakar (Jan 4, 2010)

you could have any number of issues, but its definately some sort of voltage going to ground (your case)

a HDD or motherboard is shorting to ground or your battery is leaking acid and the acidic oil is caused a path for it to short to ground but it also could be a simple pinched wire somewhere that just started touching metal.

its not good news no matter what it is so i cant offer you hope that its a cheap fix unless its in warranty

EDIT:  just saw your edit,  it could be the charging circuit in your laptop that is shorted since you didnt notice it on battery but then it could just be still there at a much lower voltage and your just not noticing it anymore because the AC voltage isnt giving it that extra kick


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## Taz100420 (Jan 4, 2010)

I agree with a grounding issue. If its not properly grounded, you WILL be the ground. Electricity is like water, flows to the path of least resistance. Except if you turn something electrical upside down, it wont go faster 

Id say something is up with ur power brick


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## Jstn7477 (Jan 4, 2010)

It is definitely an issue with your power adapter not having a proper ground. Numerous reports from Dell laptop owners with 2 pin power adapters reported being lightly shocked by the laptops if they were plugged into AC, and with a 2 prong power adapter. Dell rectified this by swapping the power bricks with 3 pin ones. Your problem is either you have a 2 prong power brick, or if you have a 3 prong adapter with a damaged ground wire, or the outlet you are plugged into is not properly earthed. Try a different outlet first.


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## @RaXxaa@ (Jan 4, 2010)

Mussels said:


> i had that as well from a CRT monitor with bad earthing (monitor died next time it zapped me, and blew me clean across the room)


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## Ptep (Jan 4, 2010)

Mussels said:


> its not voltage that you feel, its the amperage - and USB gives just enough to feel without being able to cause harm.



It still requires voltage to give you the amps, for example my bench DC powersupply will output 5v at 50Amps with you touching the outputs all day long and not feel much, because at 5v and an assumed resistance of 1.5KOhms (a fairly low resistance for a human, its usually about 100K or more, further reducing the amperage, you'd have to be soaking wet to achieve this low), the amps flowing would be 0.0033 or 3.3mA, at 100K (a more realistic resistance) you'd be looking at 0.05mA. The lowest perceivable amperage is 1.1mA. Assuming the user is not soaking wet whilst inserting his  finger between the 5V usb power and the shield i think its safe to say its not that!  

Its most likely lack of adequate grounding in the mains supply, cabling or a faulty power brick. As its an HP Pavilion its uses the standard 19V 3.42A HP PSU which are easily available on ebay and the like. It may well be worth buying a 3 pin earth socket tester (i assume you have them in US they arent too expensive, this is the sort of thing: http://www.hse.gov.uk/electricity/socket1.htm )



keakar said:


> a HDD or motherboard is shorting to ground or your battery is leaking acid and the acidic oil is caused a path for it to short to ground but it also could be a simple pinched wire somewhere that just started touching metal.



Laptop batteries do not contain acid, oils, or liquids for that matter. Most laptop batteries these days are lithium ion or lithium polymer. The only batteries that contain acid are lead acid batteries/Gel lead acid cells, which are used in cars/motorbikes/vans etc and other high current or long standby applications.


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## patheticcockroach (Jan 4, 2010)

kurosagi01 said:


> the only laptop manufacture that has the worst and poorest build quality is ACER,you should NEVER buy an ACER even it is cheapest laptop out there and their customer service is terrible.


Haha, funny I happen to have a 4 year old laptop from Acer, and guess what it gave me electric shocks too (actually, rather slight electric burning feelings), from the keyboard (somewhere around the left CTRL to ALT keys). It still work great though (but I don't really use it a lot since I've got a more recent one now).


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## karolpl2004 (Jan 4, 2010)

kurosagi01 said:


> the only laptop manufacture that has the worst and poorest build quality is ACER,you should NEVER buy an ACER even it is cheapest laptop out there and their customer service is terrible.
> Well anyways is that laptop an ACER by any chance??



no way man. acer is the best. i have a aspire 3680, and it runs like a champ! better than 2 other toshiba satellites i bought a year ago


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## Vikramsingh (Aug 2, 2016)

There should not be any voltage in between neutral and earthing point of the power supply plug. The voltage in between neutral and Line/phase can be 110V(Europe, USA) or 230V(India, UK etc). Now if the your earth and the neutral points are fine and inspite of this you are getting slight shock(approx.70 to 98 volts) then the device power card is faulty and needs replacement. This voltage leakage can be due to high humidity in the room where the printer is placed or finally the card is faulty.


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## xorbe (Aug 2, 2016)

BUCK NASTY said:


> If you can feel it, it's more than 5v.



This guy's comment is underrated.


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## GoldenX (Aug 2, 2016)

Recently a client called me, saying her notebook melted a USB keyboard connector. The battery had dried out, she plugged it and went elsewhere to do other things, when she returned the cord was laying on the table, burned...


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## Vikramsingh (Aug 3, 2016)

@GoldenX, the voltage at usb is 5V and caters low current, if the usb plastic has melted then that means probably short ckt at the usb or cheap plastic of male usb. But short ckt is detected by the laptop and computer would shutdown and wouldn't start and if usb is repaired then Windows would ask for 16 digit code.


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