Martin Gregorie  wrote:
> On Sun, 28 Feb 2021 19:29:00 +0000, bob prohaska wrote:
>
>> For some time  I lived with a an erratic scroll wheel on a Pi4.
>> Anybody got a hint what might be going on? I can understand a USB hub
>> not working right, but it's much harder to understand how it could work
>> right for pointing and wrong for scrolling.
>>
>> The mouse and keyboard are both elderly Dell take-offs from scrapped
>> computers. The keyboard is model sk-8125, the mouse is model mo56uo.
>>
>> Thanks for reading, and insights appreciated.
>>
> I had the same problem recently with a Logitech M105 mouse: scroll wheel
> was erratic, but clickers and optical tracking were fine. The problem
> turned out to be a mouse full of hair and dust that interfered with the
> optical sensors on the scroll wheel. Taking it apart, there's one screw
> that holds the Logitech together, cleaning out the collected gunge inside
> it and reassembly fixed it completely.
>
> I've had consistently good experiences with the Logitech mice: its been
> my goto brand fir at least a decade.
>
> Or, there are plenty of that model mo56uo Dell mice on eBay for around
> $US 8
>

After reading the replies to this thread I decided to try putting
the USB cable for the mouse back into the hub port on the keyboard.
It was meant to be a null experiment, replicating the original problem.

To my utter surprise, the mouse scrollwheel seems to work perfectly.
It looks as if the solution was merely to re-seat the connector.
Evidently it was some sort of bad connection, much to my astonishment.

Thanks to all for reading and replying!

bob prohaska

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