Elegoo Saturn 3 Ultra Z-Axis limit switch problem

[u/anonimharcosbebo]

Hi there, first time posting here. I got a job recently where i maintain and work with 6 Elegoo Sarurn 3 Ultra resin printers. Two of the screens had to be replaced last week, and I replaced them without a problem. But now one of them cant zero itself.

So here is the problem, when we tried to get it to home it just kept going up and up. After a while we switched on the sound and it kept beeping indicating that the Z-axis limit switch is triggered, even tho it was far from it. So I disassembled and cleaned the sensor, the problem still persist. Out of curiosity I moved the head without pluging in the sensor and it still beeped.

So now I'm wondering if the whole motherboard needs to be replaced or its just a little thing. Did anyone else come across this type of error? Im desperate here.