Xiaomi Vacuum Robot V1 - Cliff Sensor Error 4

Disclaimer:
Performing this repair on your own will void the warranty of the product. Do it at your own risk. It's a risk worth taking for me because the warranty for my vacuum has expired long ago.
The function of the cliff sensors are to let the vacuum robot knows it's proximity to the ground so that it can avoid falling off a stair or step. I have wiped all the sensors clean and the vacuum robot was on a flat surface but my Xiaomi Vacuum Robot V1 keep saying "Error 4! Wipe the cliff sensor clean and move the vacuum to a different place" and it refused to operate. I did some googling and my research suggested that I should replace the cliff sensors. So I purchased both right and left sensor sets from AliExpress. Product link below:
www.aliexpress...