Meter Issue in Meyra Optimus 2

This situation concerns model 2.322

The issue with the meter in my electric wheelchair appeared, so to speak, at my request in the 12th year of use. It started with a flat tire in the rear left wheel. After patching the inner tube, the display did not show speed while driving, and the distance traveled was not counting. I thought that after so many years, something might not be connecting, or something might have corroded. I asked a friend to disconnect and reconnect the cable from the joystick to the control panel located under the seat. The difficult access to the plug and lack of experience led to an improper connection of the cable, resulting in a short circuit in the joystick casing. I could smell burnt plastic, and the casing became warm. The wheelchair could not be turned on, let alone driven.

I contacted Meyra's service and found out that a new panel with a joystick costs 4,450 PLN, and a refurbished one costs 3,200 PLN. These prices shocked me, but fortunately, I received contact information for Mr. Dawid Rosołowski from FAZA, who repaired the damaged panel for 550 PLN (July 2019).
And what about the speed readings while driving and the distance traveled? It turned out that during the tire change, a tiny magnet that acts as a sensor was displaced. This magnet, the size of a Tic Tac, must be placed in the correct hole of the rim to be able to connect with another sensor located near the left rear wheel.