Troubleshooting Dolphin S300 "DC In Voltage" error

[lightmaster]

My Dolphin S300 is acting up. Runs for about 10-30 seconds in cleaning mode, but runs perfectly fine driving it manually. I noticed an error message in the app that says "DC In Voltage". I checked the impeller for any obstructions, but it was clear.

I stumbled upon this troubleshooting guide (How to Troubleshoot a Dolphin Pool Cleaner - INYOPools.com), however the part about the PSU seems to be for an old model. Mine has 4 pins with voltages ranging from 7-29V depending on which pins I test. Does anyone know the correct voltages on the power connector to the robot or could test measure their working one for me?

On mine, I get
1-2: 17.2V
1-3: 12.1V
1-4: 9.6V
2-3: 29.4V
2-4: 7.5V
3-4: 21.8V

 

[KenKasza]

Did you take those readings directly at the power supply or at the end of the cable? Do both and compare to ensure you don't have a cable issue.

 

[lightmaster]

Both I tested both at the power supply and the other end of the cable, same readings for the 3 wires that are inside the cable. The connector on the PSU has 4 pins, but the cable has 3.

Bigger issue right now is that I unplugged the servo from the robot's control board, and apparently that connector can physically plug in either direction, so not sure which way it's supposed to be.

 

[lightmaster]

Got the servo connected back right. Figured out which wire is DC+ and which is DC-.

Think it's the impeller motor. Made a really odd grinding sound while turning, and when powered off, does not rotate smoothly by hand.

 

[KenKasza]

I believe pins 2 and 3 are your main power at ~30VDC. The third line (pin 1 or 4) should be signal, and should use the same ground as the power supply, either pin 2 or three. You should be able to determine GND by looking at polarity of pins 2 and 3.

Try running the impeller motor with the impeller removed. Ensure the impeller is not rubbing against something.

 

[lightmaster]

Try running the impeller motor with the impeller removed. Ensure the impeller is not rubbing against something.

I disassembled the impeller motor. One of the bearings in it is seized up. Gonna try to find a replacement bearing and see if that gets it working.