Replacement LCD Display Screen for Autohelm Raymarine ST4000 Control Head Z140

Restore the display in an original Autohelm, Raytheon, or Raymarine ST4000 autopilot control head with this replacement LCD screen. It is intended for repair of the early ST4000 control unit identified by reference number Z140.

This listing is for the internal LCD panel only. The complete ST4000 control head shown in the application photographs is not included.

𝗣𝗿𝗼𝗱𝘂𝗰𝘁 𝗗𝗲𝘁𝗮𝗶𝗹𝘀

• Product type: Replacement segmented LCD screen
• Application: Marine autopilot control-head repair
• Compatible brands: Autohelm, Raytheon, and Raymarine
• Compatible model: Original ST4000
• Control-head reference number: Z140
• Approximate screen size: 48 × 19 mm
• Installation type: Internal LCD replacement
• Estimated installation time: Approximately 15–30 minutes
• Condition: New aftermarket replacement
• Quantity: One LCD screen

𝗙𝗶𝘁𝗺𝗲𝗻𝘁 𝗔𝗻𝗱 𝗖𝗼𝗺𝗽𝗮𝘁𝗶𝗯𝗶𝗹𝗶𝘁𝘆

Designed specifically for:

• Original Autohelm ST4000 control head
• Original Raytheon ST4000 control head
• Original Raymarine ST4000 control head
• Control-head reference number Z140
• Units with a matching approximately 48 × 19 mm internal LCD

The front of the control head should be marked ST4000 without a plus symbol. Compare the housing, six-button layout, LCD graphics, screen dimensions, and internal contact arrangement with the product photographs before ordering.

𝗡𝗼𝘁 𝗖𝗼𝗺𝗽𝗮𝘁𝗶𝗯𝗹𝗲 𝗪𝗶𝘁𝗵

• ST4000+ or ST4000 Plus
• ST4000+ MK2
• ST4000GP or ST4000+ GP
• ST5000 or ST5000+
• ST6000 or ST6000+
• ST6001 or ST6002
• ST7000, ST7001, or ST7002
• ST8001 or ST8002
• Other Autohelm or Raymarine instruments with a visually similar housing

The original ST4000 and later ST4000+ use different control-head and display designs. Compatibility of the complete autopilot system does not mean their internal LCD panels are interchangeable.

𝗣𝗮𝗿𝘁 𝗡𝘂𝗺𝗯𝗲𝗿 𝗜𝗻𝗳𝗼𝗿𝗺𝗮𝘁𝗶𝗼𝗻

• Z140 identifies the complete original ST4000 control head
• ST4000 is the controller model—not a manufacturer part number for the LCD
• No confirmed original Autohelm or Raymarine part number is supplied for this replacement LCD
• This screen should be described as an aftermarket replacement unless it carries original Raymarine identification

Use Z140, the ST4000 faceplate marking, screen dimensions, segment pattern, and connector arrangement together when confirming compatibility.

𝗖𝗼𝗺𝗺𝗼𝗻 𝗦𝘆𝗺𝗽𝘁𝗼𝗺𝘀 𝗧𝗵𝗶𝘀 𝗣𝗮𝗿𝘁 𝗠𝗮𝘆 𝗥𝗲𝗽𝗮𝗶𝗿

• Faded or weak display
• Poor LCD contrast
• Sunburned or darkened screen
• Discolored display background
• Cracked LCD glass
• Missing or incomplete segments caused by a failed LCD
• Display that becomes difficult to read in daylight

𝗧𝗵𝗶𝘀 𝗣𝗮𝗿𝘁 𝗪𝗶𝗹𝗹 𝗡𝗼𝘁 𝗥𝗲𝗽𝗮𝗶𝗿

• No electrical power to the control head
• Failed LCD illumination or backlight components
• Worn or damaged buttons
• Defective elastomeric contact strips
• Corroded PCB contacts
• Damaged LCD-driver circuitry
• Water-damaged electronics
• SeaTalk communication faults
• NMEA data problems
• Fluxgate-compass faults
• Rudder-reference problems
• Wheel or tiller-drive faults

If the existing display has missing segments, inspect the original contact strips, PCB contacts, and display-driver circuitry before assuming that the LCD is the only failed component.

𝗜𝗻𝘀𝘁𝗮𝗹𝗹𝗮𝘁𝗶𝗼𝗻

No special repair equipment is normally required, but careful handling is essential.

Basic procedure:

1. Disconnect all electrical power to the autopilot system.

2. Remove the ST4000 control head from its mounting location.

3. Open the housing carefully and note the position of every internal component.

4. Photograph the original LCD, contact strips, diffuser, and PCB before disassembly.

5. Remove the original LCD without damaging the surrounding components.

6. Inspect and carefully clean the PCB contact surfaces.

7. Reuse the original elastomeric contact strips only if they are clean, undamaged, and flexible.

8. Position the replacement LCD in exactly the same orientation as the original.

9. Reassemble the display evenly to maintain uniform contact pressure.

10. Test every display segment before reinstalling the control head.

Incorrect LCD orientation, contaminated contacts, damaged elastomeric strips, or uneven assembly pressure can cause missing or intermittent segments.

𝗜𝗺𝗽𝗼𝗿𝘁𝗮𝗻𝘁 𝗠𝗮𝗿𝗶𝗻𝗲 𝗦𝗲𝗮𝗹𝗶𝗻𝗴 𝗡𝗼𝘁𝗲

Inspect the case seal, gasket, and sealing surfaces while the control head is open. A damaged or improperly installed seal can allow moisture into the electronics.

The listing does not indicate that a new housing seal, gasket, or contact strips are included. Replace damaged sealing components separately and make sure the housing is properly closed before returning the controller to marine service.

𝗣𝗮𝗰𝗸𝗮𝗴𝗲 𝗜𝗻𝗰𝗹𝘂𝗱𝗲𝘀

• One replacement LCD screen

𝗡𝗼𝘁 𝗜𝗻𝗰𝗹𝘂𝗱𝗲𝗱

• Complete ST4000 control head
• Elastomeric contact strips
• Circuit board
• Keypad or buttons
• Backlight components
• Diffuser or reflector
• Front lens or housing
• Gasket or case seal
• Sun cover
• Mounting hardware
• Fluxgate compass
• Rudder-reference sensor
• Wheel or tiller-drive assembly
• Installation tools