Which Siemens Sinumerik systems are compatible with LCD upgrade?

Siemens Sinumerik 810, 810D, 820, 820M, and 840D (Power Line) systems are all compatible. Models 6FC3988-7FA20, SM0901, and 579417TA are direct replacements.

What power does Siemens Sinumerik CRT use?

Important: Siemens Sinumerik CRTs use AC 110V or AC 220V power, NOT DC 24V like Fanuc or Mitsubishi. Our LCD modules include a built-in AC power supply compatible with 110-220V. Confirm your machine voltage before ordering.

What connector does Siemens 6FC3988-7FA20 use?

Siemens 6FC3988-7FA20 uses a DB-25 (25-pin D-Sub) connector for video signal. Our LCD module includes a matching DB-25 connector for plug-and-play compatibility.

Siemens Sinumerik CRT to LCD Upgrade Guide

Published: June 27, 2026

Siemens Sinumerik CRT to LCD upgrade module

Siemens Sinumerik 810, 810D, 820, 820M, and 840D (Power Line) controls are among the most reliable CNC systems ever built — and their aging CRT displays are now failing. The 6FC3988-7FA20, SM0901, 579417TA, and 6FC4600-0AR04 models are widely used across these platforms, including 8.4-inch, 9-inch, and 10.4-inch industrial control CRT form factors.

Critical difference from Fanuc/Mitsubishi: Siemens Sinumerik CRTs use AC 110V or AC 220V power, not DC 24V. Our LCD modules include a built-in AC power supply for direct compatibility. Confirm your machine voltage (110V or 220V) before ordering.

⚠️ Important: Unlike Fanuc (DC 24V) and Mitsubishi (DC 12/24V), Siemens Sinumerik CRTs use AC mains power. Our LCD modules handle both 110V and 220V automatically with built-in PSU. DB-25 connector for signal. $399 outright, 18-month warranty.

Siemens CRT Model Cross-Reference

Model	CRT Type	Size	Interface	Power	LCD Size	Price	Compatible Systems
6FC3988-7FA20	Monochrome	9"	DB-25	AC 110/220V	8" LCD	$399	Sinumerik 810D, 840D
SM0901	Monochrome	9"	DB-25	AC 110/220V	8" LCD	$399	Sinumerik 810, 820
579417TA	Monochrome	9"	DB-25	AC 110/220V	8" LCD	$399	Sinumerik 810D, 820D
6FC4600-0AR04	Color CRT	10.4"	DB-25	AC 110/220V	10.4" LCD	$399	Sinumerik 840D sl

CRT Failure Symptoms

Symptom	Cause	Action
No display, LED off	Power supply failure	LCD upgrade
Dim image	CRT aging	LCD upgrade
Flickering	Flyback / HV	LCD upgrade
Geometry distortion	Deflection circuit	LCD upgrade

Specification Comparison

Spec	Siemens CRT	Kongto LCD
Resolution	640x400	800x600
Brightness	~200 cd/m2	350-450 cd/m2
Lifespan	~15,000 hrs	50,000+ hrs
Interface	DB-25	DB-25 direct

Siemens 6FC3988-7FA20 DB-25 connector interface

Installation

1. Power Down

Turn off Sinumerik system. Unplug AC power. Wait 2 minutes.

2. Remove CRT

Unscrew the CRT housing. Disconnect DB-25 signal cable and AC power wires.

3. Install LCD

Mount LCD module. Holes align 100% with original CRT positions.

4. Connect

Plug DB-25 cable into LCD module. Connect AC power. Keyed connectors prevent errors.

5. Test

Power on. LCD displays automatically. Adjust OSD.

Need a Siemens Sinumerik LCD upgrade?

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