Use this guide to quickly identify and resolve CM750 error messages, warning symbols, and status indicators—before you call support.
Don’t guess what that flashing icon means—here’s what to do
When your CM750 shows a red or yellow icon on the main screen, it's warning you about a fault or system status that needs attention. Knowing what each symbol means—and how to fix it—can save you hours of downtime and avoid unnecessary service calls.
This article lists the most common fault and warning icons, explains what causes them, and gives you clear actions to resolve them.
CM750 Status Icons Explained
| Icon | Colour | Meaning | What to Do |
|---|---|---|---|
| ⚠️ Triangle with Exclamation | Yellow | Warning: Non-critical issue (e.g., low solvent) | Check levels, review active warnings in menu |
| ⛔ Stop Symbol | Red | System Fault: Operation blocked | Open fault log and follow specific error code guidance |
| 🔋 Battery Symbol | Yellow | CMOS battery voltage low | Replace CMOS battery to avoid settings loss |
| 🛢️ Ink Drop Symbol | Yellow/Red | Ink level low / empty | Refill ink tank immediately |
| 💧 Solvent Drop | Yellow/Red | Solvent level low / empty | Refill solvent tank with compatible makeup |
| 🔄 Circular Arrow | Yellow | Viscosity too high/low | Check solvent consumption, restart VMS routine |
| ⚡ Lightning Bolt | Red | High Voltage Fault (EHT) | Inspect charge electrode, cable, and restrictor |
| 🧲 Magnet Symbol | Yellow | Gutter fault / missing continuity | Clean gutter, inspect sensor wiring |
| 🌡️ Thermometer | Yellow | Temperature warning | Ensure printer is within ambient spec (10–35°C) |
| 💻 Laptop Icon | Yellow | Serial/PLC communication fault | Check cable connections and protocol settings |
You can find the full icon list and fault history under
System > Fault Log.
Top 5 most common faults (and how to fix them fast)
-
Gutter Fault
➤ Clean the gutter and sensor, check for ink build-up or disconnected wires. -
Charge Error (EHT)
➤ Wipe the head, inspect charge electrode, confirm no ink residue near nozzle. -
Ink Low Warning
➤ Top up with the correct Needham fluid. Do not mix inks. -
Viscosity Out of Range
➤ Restart the system to trigger solvent adjustment. Check ambient temp. -
Communication Fault (Serial/PLC)
➤ Confirm RS232/485 connections. Reset communication settings if needed.
How to clear an icon
-
Fix the root issue (e.g., refill tank, clean gutter)
-
Go to
System > Fault Log -
Acknowledge or clear the warning
-
Restart the printer if the icon remains
When to call Needham support
Call us if:
-
Red fault icons reappear after clearing
-
The screen freezes or won’t respond
-
Your system fails to start after fixing fluid or charge issues