Ultimate Guide to Unclogging a Severely Dried Epson 7890 Printhead

Question:
I have an Epson 7890 that worked perfectly for years but was left unused in a very dry environment for about a year. Now, no colors are printing at all. One technician says it might be a mainboard issue, but I doubt that since the printer was never turned on. I believe the printhead is just completely clogged with hardened ink. Someone suggested removing the head and dipping it about a quarter-inch into hot water, preferably in an ultrasonic cleaner. I have an ultrasonic cleaner but I'm unsure if it's safe to use. I came across your video on unclogging printheads and wanted your advice.
https://www.youtube.com/watch?v=YKmx-zBeO0A&lc=UgxR7HS5AY3BjfCHRqR4AaABAg

Answer:

Now, to address your question: it's highly likely that your Epson 7890's printhead is completely dried out rather than having an electronic fault. When a printer sits unused for a long time-especially in a dry environment-the ink inside the printhead nozzles evaporates, leaving behind hardened pigment that can block every channel. This situation often mimics more serious issues like board failure, but in reality, it's typically a severe clogging problem.

You're absolutely correct that soaking can help rehydrate and dissolve dried ink. However, extreme caution is needed:

• Depth of Soaking: Only immerse the nozzle plate about 1/4 inch in warm (not hot) distilled water or cleaning solution. Never submerge the full printhead assembly. Doing so may damage the electronic contacts or the internal piezoelectric elements that control ink ejection.

• Avoid Ultrasonic Cleaners: Although ultrasonic cleaners are excellent for metal and mechanical components, they can destroy piezo elements inside Epson printheads. The vibrations can fracture delicate structures or loosen the bond between the nozzle plate and ink chambers. Even low-power units pose a significant risk.

• Rehydration Before Cleaning: The first goal should be gentle rehydration. Wrap the bottom of the printhead in a lint-free cloth soaked in cleaning solution, allowing it to rest for several hours or even overnight. This method gradually softens dried ink before attempting any pressure-based flushing or soaking.

• Use Professional Cleaning Solutions: Specialized fluids-such as the ones available at BCH Technologies (https://bchtechnologies.com)-are formulated to dissolve ink clogs safely without damaging the nozzle coating or adhesives.

Once the printhead begins to show some ink flow during nozzle testing, you can proceed with standard cleaning cycles from the printer's maintenance menu. Avoid using aggressive flushing with syringes until you confirm the ink channels have softened; forcing liquid through dry clogs can cause internal delamination and irreversible damage.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're unable to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service via our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis, and it may take several weeks before your printer can be serviced. Our repair options include both complete printer servicing and targeted part repairs, each with clear instructions on how to proceed. However, we understand our rates may not always be the most economical, so we encourage users to start with self-help options-like researching solutions on YouTube (https://youtube.com/@bchtechnologies). You can find videos easily by using the search icon next to "About" on our channel page.

Thank you again for your thoughtful question and for trusting BCH Technologies. We deeply appreciate your continued support and engagement with our content-it's customers like you who help us continue advancing the field of printer maintenance and repair.