Instructables

The Extreme Desktop Computer Prank

In this article, I will show you how to prank someone who doesn't know too much about computers.  It's extreme because most people who are scared of their computers will not be able to fix it.  Warning!  Do Not Try This On Anyone Who Knows A Thing Or Two About Computers
I tried this on thegeeke... it didn't work out too well for me in the end.......

I have two versions of this prank.  The first makes the hard drive temporarily unusable, so the computer will power up, the screen will work, but it will give an error message that will make it appear that the computer has stopped working.  The second makes it so that the computer will not even power up.  This variation works well if the victim knows absolutely nothing about computers, but if they know even a little bit, it will make it easier for them to figure out what happened.
 
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Step 1: Unplug the computer

After you have gotten access to your victims computer, you will need to unplug power.  You don't have to unplug anything else for safety, but if it makes it easier to work on, unplug whatever you have to.  It is recommended that you leave it unplugged for about 10 min. before opening it up so that capacitors have a chance to discharge, but if you are careful and don't touch anything other than what I show you, there shouldn't be a problem.
ndr19681 year ago
I know there is a "be nice" policy for replies but YOU sir, are a SICK individual!!
metal0052 years ago
@thegeekkid, it's a good instructable, but you should really try to learn about esd... if you were charged your components would be broken.
further explanation.
Just for the info on everyone who is using this.
Thegeekkid is saying

You will want to use a ground strap to make sure you don't damage anything inside the computer with static electricity (computer components can be damaged with as little as 50 V of static electricity and it takes at least 250 V before we can feel it; if I remember correctly). Slip the strap around your hand so that it is on your wrist touching bare skin, then attach the alligator clip to some part of the metal case for the computer.

but if you disconnect the power supply then the casing is not grounded and connected to your motherboard.

But as i said in my comment, good instructable and kudos
thegeekkid (author)  metal0052 years ago
Hmmm... I think you might be mistaken, but it's also possible that I am. I do not believe that the power supply is attached to the case for the ground, although it is possible. (There are no wires or anything grounding it... I know that; but it's possible that the outside part of the power supply is grounded, and since that is touching the case the case would technically be grounded to whatever the power supply is...) Also, I'm pretty sure that the case itself is a ground for static electricity. But no matter what, I would rather damage components than kill myself, and I know for a fact that it is dangerous to keep the power plugged in when you are working on a PC.

If you are concerned about both problems, than there are ground straps that actually plug into an electrical outlet and use it's ground. (And they're really fun too... most people think you are trying to commit suicide when you plug one of those in... especially if you can play the part!) ;)

I am CompTIA A+ certified, (I know it is only a basic certification, but I passed the ESD questions with 100%.) but that doesn't mean that I know everything about ESD.

I will PM thegeeke and ask him... I have been friends with him since grade school, and he used to do data recovery for a living. He definitely knows a thing or two about safely working on computers! :)
I have taken apart a power supply, and built a computer so that is were I get the knowledge of everything in this post :)

The ground wire the is plugged into your outlet, when it goes into your power supply that ground wire is connected to a tab )Or hole through which a screw is) on the power supply, which makes the power supply grounded.
Then the power supply case is connected to the computer case thus making it too grounded.
Finally, on the motherboard the ground connections of the motherboard are connected to the case ground thus making it too (Parts of it) grounded.

*Goes to read http://www.instructables.com/id/How-To-Get-Back-At-A-Certain-Smart-Alec-Who-Unplug/*
thegeekkid (author)  schumi232 years ago
Right... that makes sense... but wouldn't you agree that it isn't a good idea to have the computer plugged in while working on it? Or is it a good idea? (I never have computers plugged in when I work on them... and I've built quite a few... and I've never had problems as long as I am grounded to the case... but maybe I'm just lucky)

Thanks for your input! :)
The safety side of me does unplug power supplys, and I discharge the capacitors (Unplug, then turn the computer on (It turns on for a half-second for me (Mileage may vary by power supply :) )) When I work on them.

However, the logical side of me tells me that:
a)The chances of me touching 2 contact that are both connected to the power supply are very low
b)That 5-24 volts wouldn't make a high enough amperage to hurt me if it was just going though one finger
c)I could also just press the off button on my power supply which leaves the case grounded.

Despite all this, I too always unplug computers while working on them, and should I need it I had an old power chord laying around which I removed (Pliers, hammer etc.) The 2 prongs, leaving only the Ground wire (Often green) and I connect that to my case.

P.S: All info here assumes that the power supply is closed and that there are no mains current anywhere outside of it that is uninsulated (Other then the 2 wires that go in)
thegeekkid (author)  schumi232 years ago
OK, that's almost exactly what my thought process is. :)
Thegeekkid asked me to take a look at this... And he is actually pretty accurate. The case of the computer never really is grounded to an outlet, the case itself acts as a ground for static electricity. Think about it; what happens when you have a charge built up and you touch conductive metal (even if that metal isn't connected to a ground)? You get shocked, right? The metal itself is acting as a ground. Same with a computer case. Now; in theory, since the motherboard is grounded to the case, if there was a big enough shock, it could feed back into the motherboard and brick it, but it doesn't matter whether or not it's plugged in. Now, I disagree with him that leaving it plugged in or not waiting before you stick your hand in there might kill you. There was a time (or so I am told... That was before my time) that it was true, but now the power in there might supprise you and give you spiky hair, but that's about it (although you would probably ruin the component). Now; you would NEVER open a power supply up. That could kill you.

Side note: in the pictures, it looks like he's on carpeting... If you are worried about static, don't work on computers on carpeting.

Just so you know where I'm coming from, I used to do data recovery for the US gov. I know a thing or two about working on computers safely... And our clean room didn't have outlets of any kind in it... We had special ground straps built right into our suits... Etc.
if you connect the powercord to the computer, your computer is attached to the PE (Potential earth) of your power outlet, in the power supply the grounding then is connected to the casing of the socket which is connected to the casing of the power supply, which is connected to the casing of your computer, and so on, and then it is grounded. I have 2 electrical engineering degree's, and also 1 certificate in computer technics, so I have to know this.

And opening a power supply just tickles, trust me I know XD, it can hurt for a bit if you are holding on to long.

And maybe it is just the place we are from, in europe everyting has to be grounded to the PE
I guess it's possible it's just a difference of countries... And obviously you know a little more than I do about electricity itself than I do, but I did receive my masters in computer engineering when I was 23; not to mention all the certifications I have, so I do know a thing or two about computers, and as long as you are connected to the case, then there is very little chance of any problems. If you're really concerned about causing problems (as you should be when working on someone else's computer), then use a strap that plugs into the ground of the outlet.

Anyway, good luck, and happy pranking! (Just be aware that I am coming up with an instructable on how to get back at someone after doing this that I could actually post!) (I can't really post "how to hack" on instructables, now can I?) ;)
thegeeke2 years ago
Hmmm... I think the next instructable I will have to write will be entitled "how to get back at a certain smart alec who unplugged your hard drive durring a huge production" (or something like that...) ;)
thegeekkid (author)  thegeeke2 years ago
Ouch...
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