I fixed the loosen optical unit by (double-sided) adhesive. The most "difficult" part is just the proper fixing of the optical unit to the bottom cover because holding up-side-down is neccessary...


  1. Remove 3 black adhesives and screws underneath.
    • Remove 3 black adhesives and screws underneath.

    • Lift top cover carefully

    • disconnect the white connector by the help of a screw driver or by finger to remove the cover completely

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  2. Remove 2 screws to lift-up the two metal weights
    • Remove 2 screws to lift-up the two metal weights

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    • carefully remove the black adhesive tape

    • remove 2 screws

    • lift up the entire mainboard and take care of the two black fixing points

    • you have now the mainboard and the optical unit separated

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    • the reason for my problems where that the transparent optical unit has too much space and wobbles around while shaking the mouse which results in unwanted movement of the mouse pointer

    • therefore I fixed the optical unit by double-sided adhesive

    • best way to do so is to prepare 4 stripes of THIN double-sided adhesive and stick it around the 4 sides of the window, where afterwards the optical unit is put back to its place.

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    • hold the mainboard between your finger as shown in the image

    • place the transparent optical unit as shown in the image

    • take care, that the unit is properly aligned horizontally

    • This step ensures, that the opical unit is properly aligned to the black counterpart onboard of the chip at the mainboard

    • while continue holding the mainboard, take the black BOTTOM cover and place it up-side-down to the mainboard, such that ...

    • 1.) the optical unit is placed to the corresponding window of the cover and that ...

    • 2.) the black fixing points and the two screw-supporting points properly click into the mainboard holes

    • During this 2 steps ensure, that the optical unit stays in place in regard to the black counterpart on the mainboard. If all parts are properly placed, the optical unit should stick to the black cover by means of the double-sided adhesive tape. You can support this by carefully pressing the transparent unit to the black cover.

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    • You can now directly place back the screws...

    • ...or again remove the mainboard and ensure that the optical unit stays at the place and is fixed properly.

    • After having fixed the mainboard I did a functional test by plugging in the USB calbe to a PC and text the normal movement of the mouse pointer

    • I still noticed a "wobbling" of the mouse pointer while shaking the mouse, which I could point to the bad fixed red LED --> see next step

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    • the red LED has some space / gap between the black cover and the mainboard (red circle) and therefore can move.

    • place some double-sided tape inside the gap on both side (white in the image)

    • gently press down the black cover to fix close the gap

    • to let the black cover let stay sticked to the mainboard/tape I placed some black, strong adhesive tape ontop of the black cover of the red LED to permanently press it down.

    • I wanted to be save and fixed the optical unit and the red LED with some more black tape to keep in place and avoid any movement.

    • I made again a functional test by plugging in the USB and shaked the mouse. No mouse pointer movement was present anymore --> SUCCESS!

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    • put back the metal weights and screws

    • plug-in again the connector

    • put back the top cover

    • tighten again the screews and place back the sliding tapes


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Finish Line

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Member since: 01/16/2014

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i have a slightly newer model of this mouse. the cursor was making a repeated square motion. Seems like the photodiode picked up the blinking blue LED, which I think is only an indicator for the user. The actual functional LED seems to be infrared rather than red in the new model, and placed closer to the blue LED. I fixed my problem by covering the LED more completely with opaque tape. Not sure if my explanation makes sense? This is what I deduced, with the help of the above post and some trial and error, seeing that the cursor movement correlated with the blue light blinking and that the behavior was prevented by blocking the blue light with my fingertip. Also broke the battery leads in the process and had to resolder the through-hole connections.

Albert - Reply

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