How to Replace the LCD Display on a Fanuc CNC Control (Dim, Lines or Blank Screen)

A Fanuc screen that has gone dim, developed lines, or blacked out completely does not mean the control is dead — in most cases it is just the LCD unit or its backlight, and both are replaceable in under an hour.

First: diagnose what actually failed

• Screen very dark but faintly visible (shine a torch at an angle and you can see the picture) → backlight or inverter failure. The LCD panel itself is fine.
• Vertical/horizontal lines, blocks, or a washed-out image → the LCD panel is failing.
• Completely blank, no image even with a torch → could be the LCD unit, the video signal, or the control side. If the machine otherwise boots and runs (listen for the fans, check axis enable), suspect the display chain first.

Find the correct replacement

The display unit's part number is on a label on the back of the unit — Fanuc display units are typically A02B-xxxx-xxxx numbers, and the bare LCD panel inside has its own panel number. Either replace the complete display unit (simplest) or just the panel/backlight (cheapest). Send us the number if you're unsure — we'll confirm compatibility.

Step-by-step replacement (complete unit)

1. Back up parameters and programs first — always, before touching hardware.
2. Power the machine OFF at the main breaker and lock it out. Wait several minutes for capacitors to discharge.
3. Remove the display unit: undo the bezel/mounting screws around the display housing in the operator panel.
4. Disconnect the cables — the video signal cable to the control, the power connector, and (where fitted) the soft-key ribbon cable. Photograph everything before disconnecting.
5. Fit the replacement unit, reconnect all cables firmly, and refit the screws.
6. Power on and verify: full brightness, no lines, soft keys working.

Get the parts

• Fanuc display units & accessories
• Fanuc LCD units