Litter-Robot II Repair Guide - Chapter 2: Circuit Board | RobotShop Community

This guide will help you with the replacement of the Litter-Robot circuit board. This is chapter 2 of the RobotShop Litter-Robot II repair guides.

This is a companion discussion topic for the original entry at

I replaced the motor about two weeks ago and the litter robot worked perfectly until today. Now the yellow light turns to a flashing red. What should I do now?

@Amy, In order to better help can you specify if it is flashing red or yellow?

I bought one used when I plug it in green and yellow and red lights all blink nothing will make it stop

The issue is probably with the motor, the power supply or the harness sensor.

My Litter Robot stopped working while I was on vacation and had someone watching my cats. I’ve tried your trouble shooting guide steps 4 & 5. Based on everything I read it seemed it could be the cat sensor or motor. When you finally turn it back on it goes from a yellow sold to a flashing red light after about 2 minutes. It is the same with or without the globe. I have bought and replaced the cat sensor and motor and it continues to have the same errors. It is no longer under warranty but has only been in use the last 2 years since getting new cats. So it has not had much use for its age. What might the issue be?


The red steady light is 99% due to a defective cat sensor, form our experiences.
Now if the issue persists even after you have replaced the cat sensor, you may want to verify the connection once again.
Note if the robot has been bought at RobotShop, we can repair it for you even if you are no longer under warranty.
You will only be charged the shipping fees and the repair fees (125$)

We’ve had our litter robot II for several years and love it! Everything seems to be working fine including the sensor. The control panel doesn’t look like it was damaged by urine. The llights on the front still work but the cycle, empty and fill buttons no longer respond when pressed. What could be the issue?

There is probably an issue with the motherboard. You will have to replace it and see.
You can buy a motherboard HERE

I’ve got a litter robot II. All three lights are blinking simultaneously and I’ve read in the troubleshooting section of the manual that this is because the litter robot can’t find the home or dump positions. What would I have to replace in order to fix this issue?

Hi Steven,

The issue could be caused by the whole harness wiring or the motor.
We would need to proceed with further troubleshooting.
You may contact us via our support center.

I have the same problem. Did you figure out what it was?

3 Blinking lights can be caused by the power supply which is not supplying enough power for the motor.
It can be caused by the motor itself (remove the globe and let the robot perform a cycle, you should be able to see if the motor is making abnormal noise or is able to turn)
Also, verify if the motor’s gear is loose.

I have a Litter Robot II that recently stopped working. No lights when plugged in, doesn’t cycle when the power switch on the back is flipped, and won’t cycle when the cycle button is pushed. I verified 15v DC from the power supply, and 15v DC where the white and black wires connect to the board. Any idea on what I should look at next?