Introduction: How to Make a Prank Musical Caps-lock Keyboard

Picture of How to Make a Prank Musical Caps-lock Keyboard
Kipkay has a number of great DIY videos, but my favourite has got to be the keyboard prank.

The gist of it is to fit a fun music module from those musical greeting cards inside a keyboard and wire it to the caps-lock key to trigger the music each time the key is pressed. Do it on a friend's keyboard, unbeknownst to them, and wait for them to press caps-lock by mistake. Genius!

I'm in the ideal situation because many of my colleagues have the same standard issue Dell keyboard at work, so I took one home, wired the caps-lock key with some cheesy Christmas music and took it back to work ready to put my colleagues in the mood before the holidays. Once one is bored of it, I could simply move the keyboard to someone else!

Here's how to make yours!

- Ingredients:

  • Keyboard with caps-lock LED
  • Musical greeting card
  • NPN transistor
  • Thin wire

- Utensils:

  • Phillips screwdriver
  • Solder iron & solder
  • Electrical tape

(Version francaise)

Step 1: Choose the Right Keyboard and Take It Apart

Picture of Choose the Right Keyboard and Take It Apart

Let's start simply:
Here we have a USB Dell keyboard with the caps-lock LED next to the wire connection.
Turn it over, remove the many screws holding it in place and keep them in a safe place for now.
Take the cover off and keep it close by.
The caps-lock LED is likely to be marked as such on the circuit board. It will be easy to locate.

Step 2: Get the Musical Module

Picture of Get the Musical Module

Choose a greeting card with a great cheesy music. Christmas being only a few weeks away, I decided to put everyone in the mood early and went for Jingle Bells. Get something that plays the music quickly, because people tend to stop it early as they trigger it by mistake, so don't get something with a slow start. Also get a loud one, something embarrassing (:

Take the module out carefully and look at how the music is triggered.

Here it's a piece of paper preventing the contact from the battery. Classy.

Step 3: Find a Space for the Module Inside the Keyboard

Picture of Find a Space for the Module Inside the Keyboard

This could be tricky. I fitted mine near the arrow keys but I had to cut some plastic tabs away to make space for it and it just fitted diagonally.

Step 4: Wire the Module to the Keyboard

Picture of Wire the Module to the Keyboard
This is the biggy! That a lot of soldering steps, but it only takes a few minutes, don't worry.
Fire up the solder iron.

Cut two lengths of wire (about 15 inch each, preferably one red and one black), strip and tin them.
Cut the musical module switch away, you will replace it with the transistor.

Get the NPN transistor and hold it flat side up, pins away from you. Spread the pins apart.
  • Solder the left pin to the positive contact of the battery.
  • Solder the right pin to the other contact of the switch, leading to the music chip (big black blob).
  • Solder the red wire to the middle pin.
  • Solder the black wire to the same contact as the right pin of the transistor.

Now find the caps-lock LED, look at it carefully and find the negative and positive pins (the circuit board will likely have a + sign to indicate it). Turn the board over and:
  • Solder the other side of the red wire to the positive side of the LED.
  • Solder the other side of the black wire to the negative side of the LED.

Note that I used blue instead of black. As long as you keep your colours consistent you should be fine.

Step 5: Test It and Clean Up

Picture of Test It and Clean Up
That's it!

Now you need to test it. Make sure the board on the keyboard is in place properly, plug in the USB cable into your computer, test the keys to make sure it works ok, and... press caps-lock. Can you hear the music?

Yes? Victory! Tidy-up the wires with electrical tape, make sure you can close the keyboard properly and put it all back together. Congratulations, you're done!

No? Here are a few things to check that could have gone wrong:

  • The solder connections could be dry, weak or otherwise dodgy. Check them carefully.
  • The transistor could be the wrong one or the wrong way around, or soldered at the wrong location on the music module.
Ah that's a tough one.
You can use a screw-driver to short the left and right pins of the transistor (not the middle), you should hear the music. If not the problem might be with the music module itself.
You can unsolder the wires from the LED side and touch them to a 1.5V battery (red one to the positive), you should hear the music. If not, then the transistor is probably at fault (is it really an NPN?)

Good luck!

Step 6: The Final Product

Picture of The Final Product

The result is completely invisible. The Kipkay video suggests to tape the module to the back of the keyboard, but I think it's worth the effort to fit it inside.

Step 7: How Does It Work ?

Picture of How Does It Work ?

Ah, but how does it work?

Here's the schematics.

I've highlighted the new connections and transistor in red.

The transistor replaces the switch on the musical module. A transistor is essentially an on/off switch that turns on when it receives current on the B pin. When you press the caps-lock key, the keyboard tries to light up the LED, which sends a current to the transistor and triggers it like a switch and turns on the music! When caps-lock is pressed again, the keyboard turns off the LED, which stops the current to the transistor, which opens the circuit again and stops the music.


Thanks Kipkay for the original idea.
Check out my blog for my other projects.

Thanks for reading!


Gypsyman (author)2008-07-27

it seems like it would be easier just to program it so when you press the button your computer makes the noise. I have actually seen people do this, seems cheaper and simpler.

agent (author)Gypsyman2008-10-07

I'm going to make a program that whenever you push ANY key it plays a different sound. I'm going to put it in my flashdrive, and have it that whenever I plug it in it'll copy it to the startup programs. >:D Maybe people should learn not to leave there comps logged in when they walk off!

fastlines49s (author)agent2011-02-06


iambrad (author)agent2009-08-03

send me that program when its finished, if you ever write it.

agent (author)iambrad2010-01-17

If you're still interested, I'll write it.

iambrad (author)agent2010-01-18

 yeah, im still interested

agent (author)iambrad2010-09-23

I never really got around to making it. The main problem is that any program like this that hooks global key input is registered as a key logger in most antiviruses.

Redgerr (author)agent2010-07-08

im interested as well, would be really funny to have in your back pocket

Duct Tape Dude (author)agent2010-02-15

If you make it make the caplock say "STOP TROLLIN''

jedi pen-gui-n (author)agent2009-01-05

You can still get in if you know how. No i'm not telling here. If you want to know, go read 101 spy gadgets for the evil genuis.

mman1506 (author)2009-03-22
Alx_xlA (author)mman15062009-06-21

KipKay's 'ible: November 6, 2007 jgillick's 'ible: April 3, 2008 How did he plagiarize from something written 6 months before it was written?

mman1506 (author)Alx_xlA2009-07-27

his organial blog post was posted before kipkays instruuctable

mman1506 (author)mman15062009-07-27

it is here and check the time stamp

conrad2468 (author)Alx_xlA2009-07-20

4 months and some be relatively exact....

goldenbacon (author)conrad24682009-07-26

lol, mman got 0wned

mman1506 (author)goldenbacon2009-07-27

read 2nd coomment

lolcat360 (author)2009-01-02

I would hook it up to the E key.

Redgerr (author)lolcat3602009-06-13

omg that would be halarious! that would be so annoying and would be a great gift ahahaha... totaly

as would i

fwjs28 (author)lolcat3602009-03-14

most used letter in the english alphabet...good idea....i would prefer shift or space....there also used quite often....

oberpriller (author)2007-12-14

Awesome. My only problem is that the Caps Lock LED doesn't light up on the keyboard anymore. I guess all the current is going through the NPN transistor now. Next time I'll see if a resistor in line with the switch is enough to get the current running back through the LED.

llemarie (author)oberpriller2007-12-15

Very true! It's a shame that the LED isn't working, that's the only visible change of the keyboard. If you do try the resistor (which should go between the + connector of the LED and the Base of the transistor), I'd be interested to know if it's enough to fix the problem. The resistor of about 8k should give you 0.1mA through the transistor which is enough to trigger it, and hopefully not stealing too much from the LED.

Chris009 (author)llemarie2009-04-27

I can't get my head around resistor colour codes... can someone give me a rough idea of what bands a 0.1mA resistor would have?

bmlbytes (author)oberpriller2008-01-18

My keyboard doesn't even have a LED to light. A little box in the corner says, "CAPS LOCK ON" or "CAPS LOCK OFF" when I hit it.

downs (author)2007-12-30

Has anybody every heard of being able to re-record one of the musical greeting card chips? there are recordable ones out there but can the standard, one song chip be re-recorded? anyone? Bueller ?

thegeeke (author)downs2008-11-06

Ya, it's possible, but it's extreamly hard and I can't and won't explain it in a thread.

DYLEGO (author)2008-10-28

does the caps lock still work?

llemarie (author)DYLEGO2008-10-29

Yes, the caps lock ley works as usual. The musical interlude is a bonus, not a replacement for the uppercase. Lionel.

smashbob (author)2008-09-26

great i'ble. imagine the look on the person's face when they press caps lock. it must be hilarious. +1

ekulmeekul (author)2008-06-05

do you know what would make this circut perfect? power it from the keyboards 5v supply it would never die. Although you would need a voltage regulator. Great instructable.

fd93 (author)2007-11-13

there is a thing avalible on that makes an annoying beeping when activated or a sonic grenade but my friend wont tell me how he did it

punkatsub (author)fd932008-04-09

just click the shift button 5 times

locofocos (author)fd932007-11-26

The annoyatron or somethin like that? It's a preassembled circuit, battery and everything, that will make a little noise at random intervals. I think the intervals are between 2 and 8 minutes, but I'd have to check. It has a magnet on it to attach it to a metal surface if u want. You might be talking about the sonic grenade. When the pin is pulled, it will make a noise, whose frequency and volume can be changed. It stops when the batteries run out XD or when you put the pin back in.

jgillick (author)2008-04-03

Great instructable walk through.

Here's the original post which Kipkay got the instructions from:

jaypee4227 (author)2008-03-31

I've actually made two of these keyboards, and they are in place for tomorrow. One is for my boss, and the other is for a friend's co-worker. I would post pictures, but you can't tell a modification has been made! Thanks for such a great idea. I'll let you know how they go.

llemarie (author)jaypee42272008-03-31

Excellent! Bear in mind that it takes most people a while to press the hilarious key. My co-worker kept me waiting for 2 days before he finally pressed it (: Good luck and have fun.

tom004 (author)2008-03-21


tiuk (author)2007-11-06

This would be awesome to do to somebody who uses caps lock too much (read: at all).

speedcat13 (author)tiuk2007-11-17


man did literally ripped his caps lock key off his keyboard after bumping it so much when he types.

!Andrew_Modder! (author)2007-11-06

that wouldnt be great for me, cause i play Battlefield 2 a lot, and the caps key is the gun select, map, and spawn select, plus more lol.

Dwarg (author)!Andrew_Modder!2008-01-01

Exactly. That is a prime usage for it. MUAHAHAHAHAHA!!!

joe57005 (author)2007-11-27

i'd also try this with the new singing cards that play actual recorded songs. (this would be perfect using the hamster-dance birthday card!) unfortunately, the speakers on those are considerably larger, and i'm sure it consumes more power. but i think it should still work when powered by the caps lock led.

ukcuf (author)2007-11-17

Now if only there was a way to hook it up so that pressing either the delete or backspace button sets it off for the whole song even if you let go of the key. Your 'vicitm' (muahaha) would spend the whole day trying to type so carefully as to not make a single mistake. It would be quite funny actually as you could watch as the keyboard circulates the office, as people get annoyed and come in early to swap it for someone elses lol. :D

Deus (author)2007-11-14

maybe you can make it play with every key, except that you make it play one note each time you tab a key. that would also be a lot of work :p

jarv34 (author)2007-11-12

i love this, i was trying to think of a sound you could use that is more annoying than a musical christmas card but couldn't think of anything :) great instructable!

llemarie (author)jarv342007-11-12

You could try using one of those greeting cards that let you record your own message. You can then make it as annoying as you want (:

zachninme (author)2007-11-07

Damn, I was hoping you'd help with one of my many projects -- but I need this for Backspace :P

About This Instructable



More by llemarie:How to make a prank musical caps-lock keyboard
Add instructable to: