Automower 220 AC - losing hope
I have an ancient automower 220 ac. Year 2008. Yeah, I know it's old but it has worked just fine until this summer.
It did start up fine after the winter and I put the machine to "mow" the lawn earlier than what was really needed - I get snakes on the lot occasionally and this old fella keeps those away and also have a badger somewhere close by who likes to turn out lawn around unless the automower is keeping it at bay. But when I went in to lower the blades, pressed stop to open the hatch the first time after initial startup it just froze. On/off switch didn't do anything and keyboard was frozen - as in no input at all.
Took it apart, noticed a quarter sized burnt/melted area in the mainboard and figured that's the reason - replaced that with a new one, put everything back together, it started up fine but for some reason the mower just kept mowing the same area all the time, the lowest area of the lawn. Went in to investigate, pressed the stop and ta-dah the exact same issue - everything frozen and only way to get the power off is to pull the battery connection.
Some googlin and faulty keyboard seemed to be the issue - swapped the keyboard, everything working again - until I hit the stop button. Okay so microswitch next, I took the switch apart tested it with multimeter and seemed to work fine, but everything back together and same thing, starts up, mowes the same area and freezes when I hit stop.
The wiring harness between mainboard and keyboard looked like it had taken some heat damage. But the plastic around the wires was not melted, just blackened. So I replaced the wiring harness and the microswitch. But everything back together and nah, still the same friggin issue, stuck in that one area and when I press stop everything goes to hell.
This mower has basically been redone at this point, except the plastic chassis parts and the lift sensors but nothing works.
I tested the wheel motors and there's no difference between the motors, they seem to work fine. Opened them up and regreased a bit but the old af grease still looked just fine.
I'm just losing it at this point. I know it's old, I also know that I want to repair everything if I can to not have to buy a new one. At this point I've passed the point of no return expenses wise so that the amount of €'s I've dumbed to this is now about the same as a new second hand automower would've been.
I just can't figure out what keeps causing this freezing of the mower.
If I swap the old keyboard in after the new one has frozen, the mower starts to work again - until the stop is pressed again. If I try to reconnect the same keyboard that froze it doesn't work - however if I throw in the other keyboard, everything starts working again, until the stop is pressed.
Either this is some keyboard internal memory problem or actual black magic..