How to make a prank musical caps-lock keyboard

Step 4 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.