I like to take my Logitech F710 wireless game controller with me in my backpack; but, this often results in the sticks / buttons being pressed and the batteries drained. The F710 doesn't have a switch of its own and the sleep function only works if nothing is being pressed. I don't know how many times I've pulled it out of my bag to play and had dead batteries.
My son's solution is to take the batteries out each time which leads to a broken battery cover like all the remotes in the house.
I inserted an small switch in the power circuit which solved the problem.
Step 1: Gather Supplies
You will need some basic electronics tools: a soldering iron, needle-nose pliers, 22 gauge hook-up wire, a small drill bit, and a switch. I found both of these from Radio Shack fit nicely:
275-0007 .3A 6VDC Slide Switch DPDT
275-0032 SPST - Submini Slide Switch 2ea
I used the first one because its smaller size made the controller appear less altered but the second one also fit nicely in the same hole that I carved out with some hobby files. You can try them both and see which one you like best.
And of course, you need the Logitech F710 Wireless Gamepad.
Step 2: Open the Belly of the Beast
There are five small Philips head screws (one in the battery compartment) to take the back cover off. (Try to keep the device upside-down so that all the control buttons don't fall out, or you get to figure out how the go back in by looking at the product image page.)
Step 3: Cut a Hole for the Switch
Remove the metallic tape from the back cover. We're going to file a hole here so it would be in the way.
(I'm not really sure why the tape is there at all. My guess is that it dampens the wireless signal some to get it bellow some FCC threshold or possibly scatters the signal for better angular performance. I couldn't measure any difference either way without it.)
Line up the switch in the middle of the back cover. Make a couple of quick marks at the edges, then file the plastic away until the switch fits nicely. It should be close but not tight. The top of the switch should be flush with the edge of the back cover.
You also need to file the small ridge on the main body (not shown). This ridge makes a tight edge with the back cover and there is some overlap so it won't close nicely if you don't file it flush with the edge where the switch will be.
Step 4: Option B - the Larger Switch
The larger switch fits nicely under the main board (if you loosen the board screws it makes it easier to get the switch under it). The toggle of the larger switch, travel included, is the same size as the smaller switch's body. That means that they both work with the same hole you've already made. So if you like this look better, then get the bigger switch. be careful when running the wires because it gets pretty tight when the device is closed. You won't need to use the screws to mount it because it fits really nice - just put a bit of hot glue on the ends to hold it in.
(If you're wondering about filing on the main body from the last step, it's the thin grey ridge directly under the toggle in these shots.)
Step 5: Break the Circuit to Insert the Switch
I chose to break the circuit between the two batteries since this is on the back cover that my switch will be glued to. If you use the larger switch, you probably will want to cut somewhere on the main body - maybe the positive battery terminal?
The coiled spring just connects the two batteries. Pop it out and cut it right in the middle. Bend the coils as shown and drill a couple of small holes in the back cover where the springs will go just a little further out of the corner than the center of where the coil will be. The idea is that the spring of the coil will now hold the wire tight into the corner (originally both coils supported each other). If you don't get it right the first time, it's not a big deal. Just play with it until you get both coils to stay in position tightly by themselves. You don't want to have to play with them every time you change batteries.
(If you don't have a small enough drill bit, use a trick my wife taught me. Grab an unbent paperclip with your pliers and heat up the end with a lighter. It will push through the plastic like butter.)
Step 6: Solder the Switch
Solder leads onto the two bottom left terminals of the switch. These work best because when the device is reassembled, the main board and antenna board are right in this area. Seal the connection up nicely with electrical tape or shrink wrap. (If you short to the main board from your switch, it will fry the device and melt the battery terminal mounts. Guess how I found that out?)
Bend your terminals down and cut off the other ones.
A little hot glue around the switch will hold it in place very well. Once it cools, just trim off the extra with a hobby knife.
Step 7: Route the Wires to the Curcuit
Tuck the wires behind the X-D switches plastic slider and down through the support stands. Trim the battery connection coils so there is no excess that can reach the main board. Solder one lead to each of the battery connection coils. Cover these ends with tape or shrink wrap so there's no short later. You also need to insulate the back of the switch so I just put a little hot glue back there to cover the switches case.
Step 8: Put It Back Together
Carefully, put the back cover on. Make sure that your wiring isn't messing with any buttons. You also have to make sure the X-D switch lines up with the internal switch (just put them both left or right). Put all five screws back in (when working with small screws in plastic, it is good practice to lightly turn them counter-clockwise until they fall into their original threads. That way you don't cut new threads every time which will wear them out after a few times).
Put in some batteries and try it out. With the switch off, nothing should happen and your batteries won't go dead in your backpack. Turn it on and you are up and running.
(The Logitech Profiler will say that the device is not in the D position if it is turned off. Just turn it on and then you can program the buttons like normal.)