Logitech Cordless Optical Trackman - Mouse Wheel Button Replacement

The Logitech Cordless Optical Trackman is one of my favorite pointing devices (the others being the Logitech Trackman Marble Mouse and the Kensington Orbit Trackball with Scroll Ring). Unfortunately, the wheel button tends to go bad fairly quickly leading to it being difficult to get it to click and to double and triple clicking when you do. Even more unfortunately, my (generous) Logitech warranty is finally up and the model has been discontinued. Now they sell for several hundred dollars and the new wireless trackball from Logitech is a thumb trackball which I don't find as comfortable.

Fortunately, replacing the faulty switch is doable. While not a 'learn to solder' project due to the ease with which the solder pads for the switch are lifted, but if you are fairly deft with a soldering iron, read on.


Problem one with replacing the switch is that the Zippy microswitch Logitech uses is not readily available. Occasionally rebuild kits appear on eBay and Amazon but they tend to be overpriced. An exact match from a different vendor doesn't seem available either. Both my father and I have found the E-Switch TL3302BF180QG to be the closest match, so that's what we'll use.

Today's victim is my oldest (of the three I own), and seriously gross and worn. Disassembly starts with the four self-tapping screws in the bottom.

After their removal, the unit should separate easily. Be mindful of the ribbon connecting the top and bottom. Remove the two screws holding the top PCB to the top shell, and wiggle the whole assembly free. Note the two switches (forward and backward) which are friction fit to the top shell, as well as to the mouse wheel assembly. Undo the ribbon cable if you haven't already.

'SW3' is the one we are interested in replacing. Unfortunately its proximity  to 'SW1' makes its direct removal difficult, if not impossible. So first, we remove SW1. Luckily for you, Logitech chose to use 'just enough' solder, so a quick application of heat followed by a solder-suck should be enough to undo each solder joint. Once the solder has been removed, wiggle SW1 out.

We now have easy access to SW3. As mentioned above, the solder pads on this board seem extremely fragile. I have tried the heat and solder-suck method, but it almost ruined the pad. I highly doubt desoldering braid would fare any better. Instead, use all the space we've opened up and clip the switch leads. Then heat and suck up the remains.

Now we're ready to solder in the new switch. You are probably tempted to just center the new switch on the pads and call it a day. Don't do this, your mouse wheel button probably won't work. Take a look at the bottom of the wheel assembly.  If you center our new switch, the actuator  fits right in between the two cross bars, preventing you from being able to click the wheel without mashing it far down into the body.

 Instead, you need to solder the offset either nearly as far back as you can, or as far forward. I find it feels better offset toward the back (click action is more satisfyingly clicky), but feel free to experiment.

Once you have your new SW3 installed, replace SW1 (don't forget this step). Reassemble the mouse wheel assembly and attach it to the PCB. Reattach the side switches and make sure you can click the wheel button. At this point, you can either reattach the ribbon cable, or replace the assembly in the top shell and then subsequently attach the ribbon cable. Both are fiddly in their own way.

When screwing the PCB to the top shell, take care to not overtighten the larger rear screw. If you do this, the PCB deflects the switch away from the wheel assembly, and you won't be able to click it. Instead, tighten until it just makes contact with the PCB.

Put the two sides back together taking care not the route the ribbon across a screw hole. Pair the unit with your computer, and ensure all the buttons work.