Hello, which spring are you referring to? In the 2nd photo of step 13, there is a red arrow pointing to it. It's quite simple; each plastic part has a support for the spring. I recommend placing it first in the dark part and then adjusting it in the transparent part. You can see in the last image of point 14 that the spring is quite tight in the dark plastic. If you are referring to the spring that assists the motor rotor, take a look at the 1st image in point 14. It appears to be fitting well in its place. Best of luck!

Hi, thanks! See Picture 1 from step 14: The red arrow shows you where the spring goes, notice that the tips point to the left in the image.

All best!

You're welcome! I'm glad to hear that the guide was helpful to you in taking apart and cleaning your mouse. It can be a bit daunting to take apart an electronic device for the first time, but it sounds like you did a great job. It's definitely satisfying to fix something yourself and make it like new again. As for the lost screw and extra screws, those things happen even to the most experienced tinkerers! Hopefully, your mouse will continue to work well for you for years to come. You're welcome! I'm glad to hear that the guide was helpful to you in taking apart and cleaning your mouse. It can be a bit daunting to take apart an electronic device for the first time, but it sounds like you did a great job. It's definitely satisfying to fix something yourself and make it like new again. As for the lost screw and extra screws, those things happen even to the most experienced tinkerers! Hopefully, your mouse will continue to work well for you for years to come.

Hi.

Did you verify this problem by trying the following?

1. Installing and config the button with Logitech Logi Option+ Downloads - MX Master Wireless Mouse – Logitech Support + Download

2. Checking the native mouse settings in the operating system (Windows, Mac or Linux).

3. Test the mouse (see the menu, you can test each button independently) Mouse Test - Check Mouse Button, DPI, Sensor, and Double Click (clickspeedtest.io)

Hi Mike! Look at the 1st picture in the step 14. With a red arrow, that is the first spring (or strap, I don't know what's is the name for that), It's a support for the "rotor motor cover" (step 13, 3rd picture).

A 2nd spring (step 14, 3rd picture) is a support (or "shock absorber" maybe) for the scroll wheel, It's is located inside the black plastic piece.

Thanks you!!!

Can be used without the lithium-ion battery, just like a normal wired mouse

Hello!! It is a spectacular product, with its mistakes (nothing is perfect ;)). The fundamental objective of this guide is simply to answer the question How does it work, what is inside? It can serve as a guide to clean it (either both scrolls or the button contacts), change the battery, etc. Everything that can contribute to extend its useful life much more.