There should be two sensors inside. One of them is dirty, probably. If you already tested the cable, then, I suppose, you already disassembled the mouse and inspected everything. Then maybe one of sensors is broken. But if you do not inspect it too much, then look this disassembly video, it will give you an idea:
If the wheel is spinning fine, chances are a sensor is bad or a bad contact in the board, those mice are reliable, make some tests with the casing removed...
If the wheel is spinning fine, chances are a sensor is bad or a bad contact in the board, those mice are reliable, make some tests with the casing removed...
The capstans spin just fine. Already tried without the casing but nothing works. Continuity on connections in the board seems fine.
I tried swapping the UP/DOWN and LEFT/RIGHT just to rule out the wires. This time horizontal works but not vertical. Looks like a bad sensor? I thought I cleaned the sensors but I think those were the "light source" as Larry Pina mentioned on his book. The actual sensors are hidden/protected inside a black plastic. So how do I clean the sensors?
Every module has five parts: two transmitters and two receivers, and a wheel between them. You are right, receivers are hidden. Try compressed air. Also I think, the black part can be somehow removed, I am looking a picture of a disassembled mouse and see a screw at bottom (top on the image).
The screw you mentioned is for the board not for the black plastic. The plastic that covers the sensors, I'm not sure if it's removable judging just by the look of it. I'm not sure. I hope someone has already done removing it.
The screw you mentioned is for the board not for the black plastic. The plastic that covers the sensors, I'm not sure if it's removable judging just by the look of it. I'm not sure. I hope someone has already done removing it.
I disassembled my mouse, it's the same, but the PCB is yellow, not green. Produced by Mitsumi. It looks like these receiving sensors caps can't be easily removed. I think, sensors should be desoldered in pairs to remove them with their caps (I mean, pair of receiving sensors)—not easy to do. I still think the best is to use compressed air. If it does not help, then desoldering and investigating. Also, I tried to remove roller metal sticks, but can't do it—I can up only one half, and to up it in a whole it's necessary to remove sensor caps, or the wheel will be broken.