KDM20G Keypad Overlay Replacement — Step-by-Step Repair Guide

MultiCam CNC Tech Hub  |  KDM20G Keypad Repairs  |  By George  |  June 2026

The overlay on a KDM20G handheld keypad takes a lot of punishment — oils, solvents, abrasion and daily handling all take their toll. When it peels, cracks, fades or loses adhesion around the button area, the good news is that in most cases (if you repair BEFORE it gets too damaged) you can replace it without disturbing the button layer underneath. This guide walks through the complete overlay-only replacement process for KDM20G handheld keypads used on MultiCam CNC routers, plasma, knife, waterjet and laser cutting machines.

Before you start: this guide covers an overlay-only replacement — meaning the intermediate (spacer) layer and button containment layer are left intact. If your intermediate layer has already separated or buttons have been dislodged, stop here and read our guide on full button layer replacement first.

Step 1 — Disassembly

Typically, if the keypad is in reasonably good condition, the printed overlay can be removed without damaging or dislodging the intermediate (spacer) layer or the button containment layer. Begin by fully disassembling the outer housing.

• Carefully remove the LCD PCB and LCD screen. These components are easily damaged — remove them first for safekeeping before doing anything else.

• Unclip the E-Stop rear section and disengage it from the E-Stop button attached to the keypad PCB.

• Using needle-nose pliers, carefully unscrew the E-Stop locking ring. Once loosened, finish unscrewing by hand — this allows the E-Stop assembly to come apart fully.

Step 2a — Remove the Old Overlay

This is the most critical part of the process. Take your time here — rushing this step is where most repairs go wrong.

• Using a Stanley blade, pick at one corner of the overlay and begin to separate it from the PCB. Be aware that the adhesive layer you are working against is also the intermediate layer — it spaces the overlay above the buttons AND encapsulates and holds the buttons in position.

• Pull back slowly and at almost 90 degrees. Use pliers for grip at the start if needed. If you feel the intermediate layer beginning to lift away with the overlay, stop, try a different corner or direction, and press the glue layer back down before continuing.

Step 2b — Clean and Inspect

• Using the Stanley blade held at a low angle, gently scrape any remaining overlay residue or adhesive off the intermediate layer. Work softly — you are not trying to remove the intermediate layer itself, only loose residue.

• Inspect the PCB surface and check all button positions. Look for any sections of the intermediate layer framework that have lifted or shifted — press these back into place before fitting the new overlay.
• Check that all buttons are correctly seated and aligned in their cavities. A misaligned button will cause a dead or stiff key after reassembly.

Step 3 — Fit the New Overlay

• Peel the rear protective film from the new overlay's adhesive backing. Take care not to touch the LCD screen protector area — fingerprints here will frustrate you for the life of the keypad.
• Place the keypad flat on your work surface. Hold the new overlay above it using both hands — this lets you keep it flat and in position while guiding it down precisely.
• Align carefully before making contact with the adhesive. Focus first on getting the E-Stop hole (with its indent) correctly centred, then confirm left-to-right and top-to-bottom orientation before lowering.

Step 4 — Reassembly and Test

• If there is a small amount of overlay overlap — most commonly in the E-Stop cavity — trim it carefully with the Stanley blade.
• Reassemble the E-Stop components, locking ring, silver washer (correct orientation), and rear clip assembly.
• Refit the LCD screen and LCD PCB.
• Before closing the outer housing, depress every button individually to confirm free and even travel.
• Reassemble the housing fully and power up for a functional test.

Final Notes

It typically takes a few attempts to develop the feel for this repair — particularly the overlay removal and alignment steps. Don't be discouraged if your first attempt doesn't go perfectly. The most common mistake is pulling the intermediate layer away with the old overlay; going slowly and changing direction early when you feel resistance is what prevents it.

With a bit of patience this is a straightforward repair that will restore your KDM20G keypad to like-new operation at a fraction of the cost of a full replacement.