This vague but critical error means something’s wrong with valves, pumps, or ink detection. Here’s how to break it down and fix it.
Why it’s so frustrating
“Ink system error” is a generic fault that covers a range of possible internal issues. The CM750 uses it when it can’t isolate a more specific problem.
What to check first
| Check | What to look for |
|---|---|
| Fluid levels | Confirm ink & solvent are at correct levels |
| Fault log | Look for secondary errors (e.g. valve, pump, filter) |
| Pump noise | If silent, check power and fluid blockage |
| Valves | Run diagnostic test on valve 4–6, 11–13 |
How to resolve it
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Power off the printer
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Check ink lines for kinks or blockages
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Inspect and test pump operation
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Run Fill Mixer or Clean Ink System
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Clear fault log and reboot
If error returns, contact Needham technical support for service.