Canon EF-S 18-135mm f/3.5-5.6 IS STM Main Board Replacement

Introduction

In this guide, you will learn how to replace the main board in the EF-S 18-135mm lens. The main board is crucial to the correct operation of the lens, passing focus commands from the camera to the lens.

What you need

Step 1 Main PCB Board

Canon EF-S 18-135mm f/3.5-5.6 IS STM Main Board Replacement, Main PCB Board: step 1, image 1 of 3

Canon EF-S 18-135mm f/3.5-5.6 IS STM Main Board Replacement, Main PCB Board: step 1, image 2 of 3

Canon EF-S 18-135mm f/3.5-5.6 IS STM Main Board Replacement, Main PCB Board: step 1, image 3 of 3

First, detach the lens by pressing and holding the release button highlighted in the picture.
Next, grab the lens and rotate it counter-clockwise when looking at the camera.
Finally, when the camera stops rotating, pull the lens away from the camera.

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Step 2

Remove the four 5.5mm JIS #000 screws for the lens mount ring (silver ring).
Remove the two 4mm JIS #000 screws mounting the main board connector.
This guide involves removing a lot of very small screws so be sure to have a magnet board to keep track of them.

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Step 3

Using a spudger, pull the connector loose from the barrel switch ring assembly.
Set barrel switch ring assembly to the side.

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Step 4

This step involves handling sensitive electronics. Avoid static discharge.
Using a spudger, pull the five connectors out of their housing.
Use very gentle pressure when pulling connectors out of the lens main board, as they tend to break easily.