Taking apart Dell MS111-L Logitech/PixArt mouse

[sriemer]

Although it hurts me to take apart a completely unused mouse, somebody has to do it!

This mouse has a really strange mouse wheel. So better put the spring back into the correct location before closing the device. My detail picture shows you how it has to look like.

I knew it, in this Dell mouse identifying with Logitech idVendor there is also a PixArt chip.
USB IDs: USB_DEVICE_ID_LOGITECH_C077 (046d:c077)
PixArt IC: PAW3526DB-FJY2

Must be a secret collaboration between PixArt and Logitech. There is no datasheet for this one. That indicates more and more that there is Logitech firmware in the PixArt chips with the buffer overflow bug.

[sriemer]

[sriemer]

The mouse sensor is turned by 180 degree. No other mouse manufacturer does this. Logitech has control over the FW for sure!

[sriemer]

This mouse is completely different than the Dell MS111-P or the Dell MS116 inside!

[sriemer]

Mouse connected to the system:

[ 5310.036068] usb 3-3: new low-speed USB device number 4 using xhci_hcd
[ 5310.167473] usb 3-3: New USB device found, idVendor=046d, idProduct=c077
[ 5310.167480] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 5310.167483] usb 3-3: Product: USB Optical Mouse
[ 5310.167485] usb 3-3: Manufacturer: Logitech
[ 5310.181359] input: Logitech USB Optical Mouse as /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C077.0006/input/input11
[ 5310.181724] hid-generic 0003:046D:C077.0006: input,hidraw3: USB HID v1.11 Mouse [Logitech USB Optical Mouse] on usb-0000:00:14.0-3/input0

You see Manufacturer: Logitech while all other mice of this kind have Manufacturer: PixArt. You guys are definitely the ones who developed that faulty mouse FW!

[sriemer]

Left: MS111-P (rather black)
Right: MS111-L (rather grey)

Casing is different at the top as well.

[sriemer]

There is a photo sensor for the mouse wheel movement in the MS111-L.

[sriemer]

See also: https://www.youtube.com/watch?v=BGIq6y55p_E
(Taking Apart and Repairing Dell Mouse With Stuck Button)

[Radiowski]

Thank you very much! You saved life of my mouse :).