By following this instructable you to can make your very own CS:GO C4 prop.

For this project you will need:

Card
Brown paper/bags
Duct tape
Lots of hot glue
An old LCD Module
An old keypad
A 9 volt battery
Wire
Ribbon wire
A red LED
A 555 timer ic
A 1K resistor and a 2K resistor
A 100uf electrolytic capacitor
Paper to print labels on
Assorted bits of plastic and "computery" stuff

Step 1: The Electronics

This step covers the simple 555 timer circuit that provides a flashing red LED on the front of the keyboard. Simply follow the circuit diagram and solder all the components together. The 2K resistor can be exchanged for a higher or lower value depending on how fast you want the LED to blink; the higher the value the slower the blink. I recommend laying out the circuit on a breadboard prior to soldering to test everything as working as expected. Once all soldered together I added some hot glue to prevent any contact between pins of the 555 timer.

This circuit will be glued into the middle package in the next step...

Step 2: The Packages

The main bulk of the "bomb", these "C4 packages" are what all the other components will rest on. Hence you will want to use relatively thick card to make these out of.

To begin, mark out three 18cm x 17cm rectangles on your card - leaving room for a flap on one edge. Then divide the 18cm width into four equal 4.5cm sections, ruling a line down each border (this is where they will be folded). Next mark out six 4.5cm x 4.5cm squares, with a flap on each side.

Once this is completed cut out all the shapes, and score down the fold lines (on both sides of the card). This will make folding and gluing a lot easier. In three of the squares poke a small hole, big enough for a piece of wire to fit in. Taking your three lengths of "fuse" wire (one red, one black, one yellow) tie a small knot at the end of each and thread them through the holes in the cardboard squares (see picture 6). For the package with the black cable poke a hole in the centre of a side, and taking your circuit glue it inside the package, opposite the hole. Taking the wires for the LED and power thread them through this hole.

Finally with a hot glue gun, glue a square onto the top and bottom of each rectangle before folding up the shape and gluing it shut. It should now look like picture 7.

Step 3: Wrapping and Labels

Taking your brown paper bags, unfold them into a large sheet and lay them out flat on a table. Taking one package at a time hot glue a length of paper and stick it to the card, rotate 90° and glue the next side. Repeat until you have wrapped up the package with all the paper. Next take the end without the wire and neatly fold down the sides (picture 3), gluing them down as you go. Turn over the package and do the same for the top of it, however leave a small hole in the paper for the wire to come out of. For the middle package leave a hole in the middle of the paper for the power and LED cables to poke out of.

Next downsize the C4 label (picture 9) to 6.5cm x 3.5cm and print three off. Cut them out and stick them onto the packages. For the red and black packages stick them on the bottom of the rectangle, and for the yellow package rip off a corner (picture 7) and stick it on the top of the rectangle.

Step 4: Misc Bits and Pieces

This step will cover how I made the several odd bits and pieces that are needed.

For the ribbon cabling a found an old computer terminal head, cut it to size and stuck it onto the wire.

The main LCD board had four holes dremeled into it with a thin dremel bit. Two holes wide enough for an LED to fit into, and another two for the power cables.

And lastly, I cut and sanded down a blue terminal block to make the fitting that the "fuse" wires clip into.

Step 5: Finishing Up

Congrats! You're almost there.

This step will cover the finally things to be done and tidied up. Firstly a on/off switch needs to be soldered between the cable from the 9V battery and the cable to the circuit. I used a simple SPDT switch for this (single pole, double throw) and glued it at the top, on the back of the LCD. The led wires also need to be soldered into the LED (that now sits, glued into the holes you made in the previous step). I also "tidied" (if you can call it that) these wires with electrical tape, to prevent any contact between them.

Next, the ribbon cable with the block on the end is glued under the bottom right corner of the LCD. and tucked under where the keypad will sit. Another length of ribbon wire is glued, twisted, then glued again under the keypad. The blue terminal block you sanded down can also be glued on, to the right of where the keypad will go, before gluing in the 3 fuse wires. Once all this is done the keypad can be glued and zip tied onto the LCD module.

Finally two strips of duct tape stick all the packages and LCD module together. One strip goes below the module and one above. The strip above will also hold the 9V battery in place.

Step 6: Conclusion

And there you have it, your very own CS:GO C4 prop.

Although you may be very proud of your new prop DO NOT take it out in public as it is very likely people will freak out. I am not responsible for any trouble you may get into because of this.

Thanks for reading, and feel free to comment any suggestions