The Mighty Mouse is a great little mouse. However, the USB cable can get pretty knackered. Rather than buy a whole new mouse, why not give soldering a go and fix your old buddy, who has been with you for thousands of clicks? If you follow this guide, you can't mess it up, even if you're not a great solder-er.

Why sugru is good for this hack:

It's an electrical insulator
It bonds to this particular plastic

Sugru comes in because it fits perfectly into the inner cavities to hold the cable. It will also protect the newly repaired cable from coming loose and unwinding.

If you haven't heard of sugru before take a look at our site, it's full of ideas, tips and suggestions and you can also buy sugru directly from us or from the instructables store.

In this instructable, we will cut the USB cable, open up the mouse and re-solder the cables. Then we'll put some sugru into the mouse cavity to help keep the cable in place. We'll also add a protective layer on the outside of the mouse to futureproof the USB cable.

Let's get started!

Step 1: What You'll Need

This is what you'll need to fix your Mighty mouse:

Soldering iron + solder
Scissors
Flat head screwdriver
Small phillips screwdriver
Sugru
Scalpel / small knife
Wire strippers / cutters
Angled pliers / normal pliers

Step 2: Cut Off the Wire

Use your scissors to snip off the wire. Try not to waste cable by snipping it as close to the mouse as possible!

Step 3: Take Off the Ring Mount

Carefully wedge your phillips screwdriver between the mount ring and the side button of the mouse. Please be careful here, otherwise you might damage your mouse. Don't force it. Work your way around the mouse slowly and steadily, using the scalpel to lift up the ring slightly before you go in with the screwdriver. On old mice, the little hooks might be more prone to breaking. If they break, don't worry. You'll have some sugru leftover to fix them!

Step 4: Pop Off Inner Hooks

Use your flat head screwdriver again to unhook the top of the mouse's moving part (the bit that clicks). You should be able to see the two little hooks holding the moving part from swinging outward. Go ahead and unhook them both and the moving bit of the mouse should swing outwards.

Step 5: Pop Off Swivels

You'll notice that the moving part of the mouse is swinging around two points on the other side of the mouse. Go ahead and use your friend, the flathead screwdriver to pop off the swively bits on the bottom side of the mouse. Be careful, cause when you do this, one half of the mouse will pop off, but will still be attached to the top with little ribbon wires, which you'll see in the next step. You don't wanna rip these!

Step 6: Unplug Capacitive Sensors and Scroll Wheel

First, take a mental note (or even more sensibly, a photo) of how the two ribbon cables are attached to the circuit board. Then, use your pliers to unplug the ribbon cables. Be gentle with them. If you damage these cables, you probably won't be able to solder them!

Step 7: Unscrew the Circuit Board

Next, pick up your phillips screwdriver and take the 3 screws off the circuit board. This will enable you to get underneath it so you can re-solder your USB wire. All 3 screws have exactly the same length, so there's no need to replace the same one back into its original position.

Step 8: Chop and Strip Your Wires!

First, chop off the white plastic bit that held the cable in place before you unscrewed the circuit board. Then, strip both the USB cable that you chopped off in the beginning, as well as the black cable that was sitting under the circuit board.

You might have to use your scalpel to strip off the heatshrink on the black cable.

USB cables have 5 wires in total:

The crazy exposed silver braided wire.
D-, which is the green-striped wire.
D+, which is the white-striped wire.
Ground, which is the black wire.

Strip them all and prepare them for soldering by twisting the multicore (the tiny wires that make up each individual wire) round slightly so that they stay together.

Step 9: Solder the Wires

Before you solder, please make sure that you've passed your cable through the gate on the mouse mount! If you don't do this, you're gonna have to chop off your wire and start over!

Solder each wire to its corresponding brother on the other side. So red-striped goes to red-strriped, green-striped goes to green-striped, etc. Take your time whilst soldering, make sure you create a sturdy joint, because you don't wanna open that mouse up again.

After you do that, make sure you use some insulating tape to insulate the wires so that they don't touch each other when you close the mouse. This is very very important, otherwise your mouse will just short circuit!

Step 10: Insert Sugru

After you reattach the circuit board back onto the mouse, open up your sugru pack. Take 3/4 of the sugru contained in the pack and push it into the space between the circuit board and the plastic. Push it firmly so that it doesn't exceed the height of the black button. You want it to cover the wires underneath and mould into their shape, so that they can't go anywhere once the sugru has cured.

You also want to make sure that the cable has some sugru underneath it too, at the point where it comes out of the mouse enclosure.

Just make sure that it's engulfed the cables and let sugru do its job. It should hold the little cables in place, as well as insulate them. It should also hold the USB cable so that it doesn't damage itself whilst moving.

Step 11: Put the Top Back On

Remember how those ribbon cables were plugged in? Good, cause you're gonna have to put them back in their happy place. You can either do this with your fingers, or you can use the pliers again.

Once you've plugged them back in, go ahead and click the top back on. It's easier if you pop on the swivels first, and the hooks last.

When you have the top back on, I'd give the sugru one last check to see if it's moved out of place, of if it needs a bit of pushing around to fully engulf the cable.

Step 12: Close and Seal the Mouse

Once you're satisfied with your inner sugru work, put the ring back on. Use some of your leftover sugru to seal the cable and secure it nicely onto the main housing of the mouse.

Now, if you've broken the mount ring in the process of popping it off, no worries! Use your leftover sugru to create little balls and stick them around the ring. That'll hold it in place for at least one eternity.

Now admire your beloved mouse and click away at it, it will hold itself together for years to come. And if not, open it up and fix it again!