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I have had this laptop for just more than a year and never faced any problem with it until sometime back when I got a "tingling sensation" using the track pad, just around the edges. That happens only when running on AC.

When I Googled I see there seems to be a problem with this laptop. However, many posts in different forums talk about two pinned adapter as a probable cause but I have a three pinned one. The wall outlet is earth grounded properly.

Since I never had this problem, is this about faulty hardware or other environmental factors? It had been a hot day and the night is cold (but it has been so mostly this season), also I have scrapped my fingers around the nails lightly (just thinly peeled off skin) doing gardening.

I just want to know what's happening, as I cannot call the customer care till Monday. Any clues?

Update:

  1. The harder I press the track pad, the more the sensation.

  2. I got it again, even when running on battery but with the adapter chord plugged in and AC off! I unplugged it and the shock was gone. I plugged it back in and the shock didn't return! Its funny. I am not even able to see a pattern.

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    As to point 2 from your update; Especially with transformers, residual energy may be present, causing you to feel it even though it had been unplugged from the grid.
    – Pylsa
    May 5, 2012 at 20:19
  • Did liquid get inside the laptop? This can cause things to short.
    – LawrenceC
    May 5, 2012 at 20:30
  • @ultrasawblade no, no liquids around. Actually, this time my hands weren't anywhere close to being wet, not even sweat but there were times in the past when I had been careless wiping hands fully dry but funnily had absolutely no issues!
    – delluser2012
    May 5, 2012 at 20:35
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    Laptop power supplies are usually between 12V and 20V DC, and it is extremely unlikely that a laptop could give you a hazardous electric shock. However, it is possible that this laptop contains a electrical fault in the driver circuitry for the flourescent bulbs that are used in the backlight of your laptop screen. Definitely return it for service or at least call DELL.
    – Warren P
    May 5, 2012 at 21:43

4 Answers 4

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The fact that this only happens when on AC power is a bit concerning. I'd call Dell and get a replacement.

The problem is likely related to the controller for charging the battery. You could test this theory by unplugging the battery while it's plugged in and see if you still have the problem.

The other thing it could be related to is the inverter that runs your backlight. Most laptops will brighten the screen when on AC power. If this is the case, you have a potentially very dangerous situation on your hands. This is probably unlikely though, since you would likely be getting strong shocks no matter what.

In any case, call Dell and get a replacement. Also, don't use two hands at once on your track pad.

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  • Any idea why it could have appeared now, after a whole year of perfect service?
    – delluser2012
    May 5, 2012 at 20:21
  • @delluser2012, Could be anything... my guess would be either a wire rubbing against a conductive part of the shell (thinking about the backlight inverter), a piece of RF shielding that got bent and is pushing on something it shouldn't be, or maybe a problem that's been there all along that you've just now noticed after wearing down the trackpad.
    – Brad
    May 5, 2012 at 20:27
  • Thanks for the info. One more question. When you say replacement, you mean the entire laptop or just the faulty bits? I ask this because I might have information on my hdd subject to non disclosure types of thing (I bring my work home), so I don't want them to do the copying or even get close to the contents.
    – delluser2012
    May 5, 2012 at 20:45
  • @delluser: Most likely they'll erase (restore to factory contents) the drive if you send it in. I recommend unplugging the drive carrier and keeping it with you when you return the rest of the unit. Usually that's just 1-2 screws and the hard drive slides out. Remove all power sources first of course, including the battery.
    – Ben Voigt
    May 6, 2012 at 1:26
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It sounds like your laptop has issues with a ground, since the voltage on the laptop chassis is floating high. You should not have gotten an electric shock. If possible, open the laptop, and try to see if any components are electrically shorted to the laptop chassis and/or other connectors.

If you only experience the shock when the charger is connected to the laptop, then you should stop using the charger immediately and get a new one. Check the charger itself for ground faults. If you are using an ungrounded charger, there may be an electrical fault in the actual socket. Start with the charger, and work from there.

Again, there is no voltage in the laptop which is high enough to shock you. I have not seen any laptop chargers provide a DC output higher then 20 V. Look into the charger or any short circuits (either in the laptop or charger), but again, since you're getting shocked, ensure that your charger is not the problem.

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A simple test to figure out if it is your laptop or your electrical wiring, you can connect another device, e.g. a printer or a monitor - which has a three pin plug to the laptop (usb port or video out port) and if the current/vibrations/shocks are gone, it is your wiring. Because the three pin device is providing the ground.

You would do well to use a tester, or get a proper electrician to run this test for you. If it is your wiring, it is still a question whether it is your internal wiring fault or the electricity companies fault. You should first call your electricity company to get them to check that they are providing the ground/earth for you correctly. If that does not solve your problem, then unfortunately it is your internal wiring which is faulty. This could be expensive. Or you could just keep the three pin device connected and ignore the problem.

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just wrap the middle cord with plastic cover in the charger and use it. i also had this problem after doing it's working fine(no shocks)

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  • What's the middle cord?
    – fixer1234
    Jun 10, 2016 at 11:28
  • 1
    Welcome to Super User. A common mistake new users make is to answer without details of how to actually resolves the issue. Answers should be detailed and include references, as needed. Please take a few minutes to edit your answer to include details of why your answer is valid. If you need some help, read How do I write a good answer?.
    – CharlieRB
    Jun 10, 2016 at 13:28

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