Video Guide

How to check your 3.3V Rail

NOTE: If you do not know how to test and/or have the tools to test you can install this even if the board doesn’t need it with no adverse effects. This kit is installing a separate 3.3v regulator to bring the voltage in spec. These boards are notorious for having issues with their 3.3v rails being too low.

1. Turn on your printer and get access to the control board
2. Set your multimeter to DC voltage (if not auto-ranging choose a low value like 10 or 20)
3. Touch the negative (black) lead on the multimeter to the G Pin and the positive (red) lead to the 3v3 Pin. (see pic below for pins)
4. If the voltage shows 3.15V or lower, you probably need this kit. If it shows 3.2V or higher, you probably do not need it.

How to Install the Kit

Make sure to follow the installation pictures EXACTLY in terms of the wire connections.Wire color does not matter and the colors of the jumper wires supplied with the kit will vary from the pictures shown below. You will be making 3 connections from the 3v3 Fix Module to your control board. Depending on the LCD you have the installation will be different. See below.

If you have an Ender 3 S1 or 12864 LCD on your machine you will follow this wiring diagram:

If you have the stock Touch LCD you will follow this wiring diagram:

This can also work on the V4.2.2 and V4.2.7 Boards

Just test on the VCC/3v3 and GND pins on the 4 pin header next to the LCD header to see what your 3.3V rail is at, anything lower than 3.2V is usually problematic. If it is low then you can add this kit on and you can pull the 5V line the kit needs (goes to the 5 pin on the kit) from the BLTouch header V pin.

NOTE: If you already have a BLTouch on that header you will need to splice in the wires so the 3v3 fix and the BLTouch can share the V pin.

The wiring is shown below for the V4.2.2 and V4.2.7 Boards. Please note that we have seen some 4.2.2 and 4.2.7 boards with NO headers soldered in the location shown below. You must have a header soldered on in order to use this kit.