Robotic lawn mower- Gardena R40Li - Teardown

Today we take a look inside the Gardena R40Li robotic lawn mower and fix the error message: electrical problem 501

[@Beerdude26]

I had the same problem as Hans: the four screws were rusted shut. I just needed to replace the wheels. I was able to remove the covers from the wheels and could then access the wheel screws by putting the mower on its side, rotating the wheel manually and pulling the bumper part and wheel apart. This way, I had relatively good access to the wheel screws and was able to replace the wheel. I put on the wheel cover partly and manually rotated the wheel again until I could get to the third plastic clip. After slotting that in, the other clips also slotted in nicely.

[@JERandomTech]

Thanks for sharing!

Excellent, just what I need, I thought. I could remove some screws and wires and spray some contact cleaner spray. Total failure. I didn't even get past stage 1, to remove the first four screws. Two of them seem to be connected to some rubber-thingy and all that happens when I unscrew them is that the rubber gets twisted. Nothing gets loose. I guess I have to hand the lawnmover over to the repairman after all :(

[@JERandomTech]

Sorry to hear that. You could try to use some spray on the screws so that the adhesion is reduced. If the device is still covered in warranty/you want to send it in should always be the preferred option.

[@cscs9192]

Informative and good. What kind of spray did you use to clean the contacts ?

[@JERandomTech]

Thanks. Sorry for the late reply. I used contact spray to clean the contacts.

[@86Raxor]

Thanks for sharing this video and walkthrough. I have the same one. I believe the battery might have died during the winter as I did not maintenance charge it during this winter. The display does not light up Unless I move the lawnmoveer by hand, then the display lights up just as the wheels move. What does that tell me? Is it the motor/feedback/contacts or may it indeed be a dead battery?

[@JERandomTech]

I have never experienced the display turning on while pushing the motor so I am not sure wether my following experience applies to you. However, after that being said, I did exchange the battery after about 10 years as the robot didn't work and that was my first guess. To do this you do not have to disassemble the entire robot! It is shown in the beginning of the video where the battery is located. Then I measured the battery and as I did not get any voltage I exchanged it. However I'd be curious to know what happens if you put the robot in the charging station? The robot that I have usually beeps two times so it could also be that the connection of the robot to the charging station is not working properly. You can see the connection on the robot in 0:30 the copper pads to the left. After some time these need cleaning as well as on the charging station. My charging station has fins so connectivity might be improved if they are carefully bend forward a little. However this is only speculation. Hope that helped!