Siemens SINUMERIK 840C CRT to LCD Replacement

Factory Direct Upgrade Module β€” No Middleman, 2-Year Warranty, Ships Within 24 Hours

Direct upgrade path: The SINUMERIK 840C uses the same display interface as the 810/820/880 series. Our KTV-series LCD modules are confirmed compatible β€” plug-and-play, no CNC parameter changes required.

About the SINUMERIK 840C

The Siemens SINUMERIK 840C was a high-end CNC control introduced in the early 1990s, used primarily on large milling machines, lathes, and transfer lines. It features a modular architecture with separate NCU, PLC, and display components. The 840C's CRT display is a 14-inch or 9-inch monochrome/color unit depending on configuration.

After 25-35 years of operation, these CRTs are failing at an accelerating rate. Siemens has discontinued most 840C display models. Third-party LCD replacement is the practical solution.

Display Models Used on SINUMERIK 840C

CRT ModelTypeSizeStatusOur Solution
6FC3988-7FA20Monochrome LCD/CRT9"DiscontinuedKTV148 β†’
6FC3998-7FA20Monochrome CRT9"DiscontinuedKTV148 β†’
SM0901 / 579417 TAMonochrome display9"DiscontinuedKTV148 β†’
SM1200Color TFT12.1"DiscontinuedKTV121 β†’
6FC5103-0AB01CRT (DB-25)9"DiscontinuedKTV series β†’

Why Factory Direct Matters for 840C Owners

How to Order

Send us a photo of your current 840C display (front and back showing the connector). We'll confirm compatibility and send a firm quote within 4 hours on business days.

SINUMERIK 840C Quick Facts

Introduced1991
Display interfaceProprietary Siemens 20-pin (same as 810/820/880)
Common CRT size9" mono / 14" color
Common failure age25-35 years
Upgrade difficultyEasy β€” 20-30 min, plug-and-play

Frequently Asked Questions

Q: Will a 840C LCD upgrade work with my machine tool?
A: If your machine uses a Siemens SINUMERIK 840C control with the original CRT display, our upgrade module is compatible. The signal interface is the same across the SINUMERIK 810/820/840C/880 family. Send us your CRT model number for 100% confirmation.
Q: Is the upgrade reversible?
A: Yes. The LCD module connects to the same cables as the original CRT. You can swap back at any time.
Q: Do you ship to Europe?
A: Yes. We ship to all EU countries, UK, Switzerland, and Norway. Delivery 5-10 business days via DHL/FedEx.