~JN - Head Test Fatal

Overview

The ~JN command resets the printhead element error override, making printhead element failures fatal again. Acts as a toggle for ~JO, causing the printer to enter fault status if subsequent printhead testing detects bad printing elements.

Syntax

~JN

Parameters

None

Description

• Restores fatal error mode
• Cancels ~JO override
• Printer faults on bad elements
• Head indicator turns on steadily

Examples

Restore Fatal Errors

~JN

Enables fatal mode after ~JO temporary override.

Error Behavior

Fatal Mode (Normal)

• Bad elements detected → Fault status
• Printing stops
• Operator intervention required
• Printer awaits repair

Non-Fatal Mode (~JO override)

• Bad elements ignored
• Printing continues
• Quality may degrade
• Temporary measure only

When to Use

Restore to Fatal

• After troubleshooting
• Before production
• When printhead repaired
• For quality assurance

Cancellation of Override

~JN cancels ~JO:

1. Send ~JO (temporary override)
2. Test printing continues
3. Send ~JN (restore fatal mode)
4. Resume normal error handling

Related Commands

• ~JO - Head Test Non-Fatal
• ^JT - Head Test Interval
• ^SR - Set Head Resistance

See Also

• Head Test Non-Fatal (~JO)
• Head Test Interval (^JT)