Not a "pure Linux" question, nor a tragedy but I'm curious.

I have a Logitech PS/2 mouse which developed the bad habit of scrolling slowly OK but will not respond to fast scrolling.

Playing with the mouse settings did not help. Nor did trying it on other PCs.

I've had a look inside and can't see any mechanical problem. I have the skills to remove a couple of inches of cable and resolder it - done it often in the older days of mechanical mice. Could this be a broken wire problem?

In this situation I need PS/2 because I am using a PS/2 KVM. Incidentally it seems that PS/2 mice are rapidly becoming extinct. Locally I can only find Manhattan MH3 Classics and have been assured by 2 shops that they will not be reordering. So I bought 2!

I'll soon have a lot of time on my hands, recovering from spinal surgery so, if I get any advice, it will be a good way of passing a morning

Thanks in advance for any hints.

Since you have more than 1 mouse, testing whether its a physical issue with the mouse should be pretty simple?

There are little adaptors from USB to PS/2 - I even have used one for your exact reason (PS/2 KVM).

It is a little female-to-male, from USB to PS/2.