Is my laptop going to kill me?
March 3, 2013 1:49 PM   Subscribe

I got a shock from my laptop the other day and now I'm afraid to use it...

It was plugged in and I touched it and I got a pretty bad shock. My husband carefully (holding it between two rubber-soled sneakers) unplugged it and shut it down.

Then he booted it up the next day and didn't get a shock. He says that the place where the plug goes in, in the laptop, seems to be loose, and maybe that's why there is some sort of short that happens. He believes that this is the kind of situation where fixing it would require replacement of the motherboard, which would not be worth it (the laptop is a few months past its three-year warranty -- it's a Toshiba Satellite).

I really like this laptop! Could the shock have been lethal? could another shock from it BE lethal?

What should I do?
posted by DMelanogaster to Computers & Internet (12 answers total) 1 user marked this as a favorite
First, do you have a backup (or two) of everything on the laptop?
Could the shock have been simple static electricity? Or is it a metal table and it's something else that is causing the shock? Did you check the transformer/power cable for frays?
I think it's really unlikely that the power plug could fail in such a way that it gives shocks, yet is able to work.
Since it's post warranty, maybe open it up, and use some 5 minute epoxy to secure the loose socket.
As far as being lethal, it's unlikely but possible with enough bad luck (example one, and two)
posted by Sophont at 2:26 PM on March 3, 2013

There's no way a shock from it could seriously hurt you. It's under 20 volts dc with not a whole lot of current behind it. That's not a worry. What's going on here is that the case is coated with an EM resistant material which is metallic, and the jack is touching that. This creates a circuit from the positive pin of the jack through the chassis to some metallic point where it touches you... At which point you become the ground.*

That said, it sounds like the power socket has started to bust off the motherboard. This is incredibly common in laptops. I just repaired one a few days ago with the jack completely snapped off, which is generally the endgame of it being loose. This isn't hazardous in any way, it'll just cause the machine to stop working when it finally fails. Even if it does short the socket against something seriously(unlikely), it'll just trip a little internal cutoff in the power brick.

A new jack is generally around $5, but then you need to get the laptop apart entirely and pull the motherboard out to solder it in, at least in most cases. A shop usually charges around $200 to do this because its tedious, and takes a lot of time and labor. It's only really worth it if you know someone who will do it, it's a really nice laptop, or you can do it yourself.

Personally, id just keep using it until it died. I've done it in the past, and so have friends. Over 3 years is plenty long for a computer. If its into being 4, it's approaching 5 which is often as long as a regularly used laptop seems to last on average.

*best guess here, but coming from lots of experience.
posted by emptythought at 2:29 PM on March 3, 2013 [1 favorite]

This appears to be a known issue.

The Toshiba Forums link above has a comment by a moderator which says the problem can be solved with a three-pin AC adaptor plug, and which links to another TF page in which a person who does not seem to be a moderator says the effect is due to capacitive coupling in the power brick to the AC in the wall.

It's somewhat ambiguous, but I'd say it looks as if Toshiba sent the person who raised the question in the second thread the necessary 3-pin adaptor free of charge.

If it's true that this is due to capacitive coupling to the 120V AC potential in the wall, you could be experiencing a lot more voltage in those shocks than the ~20V DC you'd get from shorting a properly functioning adaptor across your body, and it would be much more dangerous AC voltage to boot.
posted by jamjam at 3:38 PM on March 3, 2013

I think the manufacturer is the place to start. You said it's a little outside warranty, but (...and I can't speak for Toshiba, but) the manufacturer of the laptops that I repair takes the threat of personal injury (and liability for same) very seriously, and I suspect that to approach Toshiba's customer relations contact from a "I'm worried because your product physically harmed me and now I'm not comfortable using it" position can mean a better chance of them repairing it for you.

Good luck!
posted by churl at 4:13 PM on March 3, 2013

jamjam, I didn't feel that static tingliness, I felt a shock. And I don't think that tingle would begin 3 1/2 years after getting that laptop, right?? it's a new problem.

I tend to think my husband is right and that it's the loose input on the laptop itself.

I"m going to take it to a computer repair place tomorrow and see what they say.

Thank you.
posted by DMelanogaster at 4:24 PM on March 3, 2013

You got the shock because you were grounded somehow; if you weren't grounded, you'd feel the tingly, clingy sensation instead as you dragged a finger across metal on the computer-- and I do speak from bitter experience here, though not with a Toshiba.

The 3 1/2 years to onset may well be because something has gone wrong with the computer proper (namely, one side of the power brick output has shorted, or is intermittently shorting, to the case, somehow), but the three prong adaptor will keep you from getting a shock even when that short does happen.
posted by jamjam at 5:05 PM on March 3, 2013 [1 favorite]

Oh wow, I revise my statement then. This could be fairly dangerous. This is a similar to grounding and capacitance issues you can have with old guitar amps. Even with a 3 prong cord, this could still be dangerous if you ever plugged it in to an improperly grounded socket, which is depressingly common in older houses.

I've gotten seriously zapped this way. I'd look in to getting a different compatible model of power supply that isn't affected by this issue on eBay. I'd also quit using it until I had that, other than to maybe charge the battery, then disconnect it from the charger and unplug the charger from the wall before use.

Scary stuff here, this can lead to you completing a 120v circuit and melting the power supply/laptop/being seriously injured. Uh, yea. Didn't expect to ever see this with a laptop.
posted by emptythought at 5:42 PM on March 3, 2013

Unless your power adapter has somehow failed, this is nothing to worry about. If you google for "ac adapter shock" you will see dozens of threads about a tingly feeling when touching a metal part of a laptop. It is nothing more than a static shock and is not life-threatening.

It occurs with any AC adapter that has only two prongs. The laptop is electrically isolated from the AC power and is not grounded to earth. That means that it floats electrically with respect to earth ground. There is a very small capacitive coupling between AC power and the laptop. The laptop may charge up to 100 volts or so and then discharge to ground through your fingers when you touch the metal chassis. Because the charge is only 100V, you will feel a tingling instead of the spark and shock you get when touching a doorknob and you are charged up to around 5000 volts. You may be more likely to experience it in the winter when the heat is on and humidity is low, allowing static charges to build up.

So there isn't anything unsafe. It is just a momentary static discharge and you should only feel it when you first touch the laptop. There isn't a continuous current flowing.
posted by JackFlash at 7:42 PM on March 3, 2013

Unless your power adapter has somehow failed, this is nothing to worry about. If you google for "ac adapter shock" you will see dozens of threads about a tingly feeling when touching a metal part of a laptop. It is nothing more than a static shock and is not life-threatening.

Allow me to retort: my girlfriend's computer would occasionally zap us, not in a slightly tingly way, in an ouch that actually hurt way. After a few months of that, one day she had plugged her computer's power adapter into the wall, and as she was plugging the other end into the computer, it not only shocked her, but put enough electricity through her hand that the muscles clenched and she could not let go - she was finally able to use her other hand to yank the cord out of her electricity-induced fist. I guess her life wasn't in danger because the current wasn't crossing her heart, but it did cause a burn and was definitely worth worrying about.

Good call taking it to the repair shop, is what I'm saying.
posted by solotoro at 4:50 AM on March 4, 2013 [1 favorite]

so solotaro, what actually happened? does that three-prong ameliorate this problem ("this problem" = a real shock, NOT tingling, really much much more than tingling!)
posted by DMelanogaster at 6:51 AM on March 4, 2013

We did three things. We switched to an outlet that had a ground (her power supply was already a three-prong), we only ever plugged it in the other way around (into the computer first while no juice was running, then into the wall), and we never put it on our lap, just on the coffee table. One of those three things worked, though honestly I'm more than a little skeptical that the socket we were using was any better wired than the first one, despite the fact that it appeared to have a ground - this was in a house in a developing country, and I'm not even sure there IS a code for wiring not to be up to here. There are bare, live wires sticking out of my bathroom wall. But whichever it was, we didn't get zapped by the computer anymore.
posted by solotoro at 11:15 AM on March 4, 2013 [1 favorite]

End of Story: I took it to my trusty repair guy who replaced the power jack without soldering. He said that on my laptop it was easily replaceable. $95 plus tax. I'm typing on it now and I'm not dead yet.
posted by DMelanogaster at 1:25 PM on March 7, 2013

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