X Axis Troubleshooting Help, Please

I have a Monoprice MSP 3D printer with the ADVi3++ 4.0.6 firmware installed and functioning. I was changing the heated bed yesterday and after that operation the y X-Axis will not home, it only moves to the right. I used a multi-meter to confirm that the X-Axis home switch is functioning. I have disconnected and reconnected the 2-pin connecter, the ribbon connector on the extruder PCB, and the other end of the ribbon connecter at the main board.

Does anyone know what pin # on the ribbon cable is the X-Axis signal to the switch? If I knew that, I could probe that pin on the Main board.

Which input pin is the X-Axis home switch?

Is there a way to view the state of the X-Axis input with the ADVi3++ 4.0.6 firmware?

Thanks in advance.
Salty Doug

Go to Tuning / Diagnosis.

That was perfect!
Switch is not made:
Switch is made:
However the X-Axis still doesn’t home.
While I look at the sensor screen I can see the X light going on and off about once per 2 seconds.
I think the main board Might be damaged.
How about you?

You mean without touching anything? If so, looks like a cabling problem. Maybe at the level of the small board behind the printer or at the level of the flat cable between this board and the printer. Look at both sockets.

Or the switch itself. See if you can pull the cable from the small board and watch the debug screen if anything changes.

Hello, I’m back from my holiday.

Before I left I cleared the EEPROM with My_EEPROM_Clear sketch then uploaded the ADVi3pp-BLTouch3-Mainboard-4.0.6.hex file from here.
Now the Xmin light is always off and the value is less than 500 when the switch is not activated.
I find it strange that there is a numeric value for the X axis limit switch. The Y and Z switches do not have values only lights, like digital inputs. Is the X limit switch an analog input?

Eric, with the switch pulled from the extruder PCB the debug screen changes very little. The indicator light is off and there is a number to the right that ranges from 431 to 434.

Salty Doug

Yes. But all analog inputs are also digital inputs.