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A5/A3S filament Sensor


The filament sensor on these printers is often plugged in wrongly into the front LCD. This causes a loud continuous beeping sound when you try to print. The printer is thinking filament has run out, and is preventing printing from proceeding.

Even if it is plugged in correctly, the connector that JGAurora has used can short circuit with the neighbouring pins causing this error.


Unplug the two wire cable sticking out of the LCD module.

You can access this cable from underneath the printer, through the cavity, or by opening up the main chassis.

If you wish to use this filament run-out feature reliably, you will either need to replace the connector with a 2-pin header cable, or turn the connector around 180degrees so that the metal contacts on the side are facing away from the other pins. Note that the JST connector they are using has three sockets, but only two are used.

The two wire cable is NOT polarity sensitive, as it goes to a simple mechanical switch that detects when filament is inserted.

The INCORRECT way the plug comes installed from the factory is shown in the image below. (Image Credit: Markus IngK - MCK) - it is still recommended to flip the connector 180 degrees to orient the metal contacts away from the other neighbouring pins.

Filament sensor pins

The pins for the filament sensor belong to the 6-pin header pins near the centre of the lcd module. The top two pins, in the right column of pins are used.

a5/filament-sensor.1518464895.txt.gz ยท Last modified: 2018/02/13 06:48 by pinchies