Run Weak Clean and print another nozzle test. If ink is still missing, repeat the cleaning. If there is no improvement after 2–3 cleaning cycles, contact a technician for support. The manual also recommends performing a nozzle test before each printing job.

If the C604 will remain unused for more than two weeks, follow the long-term maintenance procedure to reduce the risk of ink-line and printhead clogging. The printhead should be kept properly moisturized and sealed, ink tubes should be clamped, and DTF film and hot-melt powder should be protected from moisture.

The recommended operating environment is 20–35°C (68–95°F) with 35–70% relative humidity. The manual also recommends using a voltage regulator or UPS and properly grounding the machine to protect the printer.

After powering on the C604, run the white ink circulation system for about 2–3 minutes before turning it off. This helps maintain smooth white ink flow and reduces the formation of air bubbles in the ink tubes.

Before shutting down, make sure the carriage has returned to its correct position and the printhead is centered over the capping station. This keeps the printhead sealed and moisturized and helps prevent nozzle clogging.