Quality/stripes Magenta missing or purple

[ochmenno]

Dear colleagues,

we have a T830 at the customer, where we had to replace the printhead because of big black stains, black ink leakage and white stripes (missing ink).

The new printhead worked for some days, then the colours where wrong. We checked and on the status page

the magenta bar was purple. After a printhead calibration it was ok again. But it didn't last for long and magenta had a wrong colour again. We've replaced the printhead a second time. And after some days the customer complains about missing magenta and stripes again.

I can't believe that the second new printhead is defective again.

What else could it be? Does anyone have experiences with this?

Thank you.

[Meghana_10]

Hello @ochmenno, Welcome to the HP Support Community.
 

Based on your description, the fact that two replacement printheads initially produced correct colors but later developed the same magenta-related issue makes a repeat printhead failure less likely. Since printhead calibration temporarily restores proper color output before the problem returns, this may indicate an issue elsewhere in the ink delivery or maintenance system rather than with the printhead itself.
 

For your HP DesignJet T830, we recommend the following troubleshooting steps:
 

Print the Image Quality Diagnostic and Service Plots

• Compare the magenta nozzles immediately after calibration and again after the issue reappears.
• Check whether the magenta nozzle count progressively decreases over time.

Inspect the Magenta Ink Supply Path

• Verify that the magenta ink cartridge is genuine HP and contains sufficient ink.
• Check for any signs of air ingress, ink starvation, or intermittent ink flow between the cartridge and printhead.

Check the Ink Tube System

• If available through the service diagnostics menu, review ink delivery and priming functions.
• An intermittent restriction or air leak in the ink path can cause colors to degrade gradually after a successful calibration.

Inspect the Service Station

• Since the original printhead was replaced following ink leakage and print quality issues, inspect the service station assembly for contamination, dried ink buildup, or maintenance errors.
• A malfunctioning service station may fail to cap or maintain the printhead correctly, leading to recurring nozzle loss.

Review the Printer's Error and Event Logs

• Check for any ink system, maintenance station, carriage, or printhead-related service alerts that may not be visible during normal operation.

Perform a Printhead Recovery Test

• Monitor whether the magenta channel recovers after calibration and then progressively deteriorates with usage.
• Consistent degradation after recovery often points toward an ink delivery issue rather than an electrical printhead fault.

Verify Firmware Currency

• Ensure the printer is running the latest available firmware version, as printhead calibration and ink management improvements are occasionally included in firmware updates.

The next areas of focus would typically be the magenta ink delivery path, service station assembly, maintenance system, or an intermittent ink supply issue, rather than assuming a third printhead is defective.
 

Have a great day!