Canon PRO-500 can lock printing when the waste ink (ink absorber) counter hits a predefined threshold. This guide explains how to reset it.

Inside Canon printers, absorber pads collect excess ink from cleaning and maintenance cycles. The printer uses an internal counter to estimate pad saturation.

This page is prepared for Canon PRO-500. Service mode instructions are shown only when a matching series procedure is known.

What You May Notice

• Service / maintenance warning on the screen or driver
• Printer refuses to print even with ink available
• Blinking lights and queued jobs fail
• Error reappears after restart

How to Enter Service Mode on Canon PRO-500

Some Canon series require entering service mode before the ink absorber counter can be reset.

1. Turn the printer OFF.
2. Press and hold Stop/Reset.
3. While holding Stop/Reset, press and hold Power.
4. Release Stop/Reset (keep holding Power).
5. Press Stop/Reset 6 times.
6. Release Power — the printer should enter service mode.

If it doesn’t work, repeat the sequence carefully. The press count depends on the series.

Perform the Waste Ink Counter Reset

Once the counter is cleared, Canon PRO-500 should exit the locked state and printing should resume normally.

Warnings

Resetting the counter does not physically clean the absorber pads. For heavy usage, pads may eventually need cleaning or replacement.

Need a reset solution?

If your model does not show a service mode section, it means no matching procedure was found for its series.

Troubleshooting

• Use the correct Stop/Reset press count for your series.
• Repeat the service mode steps carefully (timing matters).
• Try a different USB cable/port if using PC software.
• Power-cycle the printer and try again.
• Close other Canon printer utilities while resetting.