Epson ET-8550 Yellow Nozzles Missing After Power Cleaning: What to Check Before Flushing

Question:
My Epson EcoTank ET-8550 uses Hipoo sublimation ink and sat unused for about two months. Yellow still prints, but its nozzle-check pattern has missing lines while the other five channels look much better. Two Power Cleanings, refilling the yellow tank, and a 20-minute paper-towel soak with 91% isopropyl alcohol under the head did not fix it. Should I use BCH Green or Red cleaner and the ET-8550 adapter, or check the ink supply and capping station first?

Answer:
Thank you for contacting BCH Technologies, and I apologize for the delayed reply. Printer problems can halt production, so we want to give you a careful, detailed answer. Thank you for supporting BCH and its YouTube channel.

The nozzle check confirms missing yellow jets, but it does not identify their cause. Dried ink after two months idle is possible. Air in the yellow path, restricted ink delivery, poor sealing or suction at the capping station, and printhead damage are also possible. The fact that the other channels print more completely helps narrow the symptom to yellow; it does not prove that the printhead needs replacement.

Pause further Power Cleanings and chemical soaks. Epson's ET-8550 instructions say to turn the printer off and wait at least 12 hours after Power Cleaning before another nozzle check or cleaning, and to seek support if repeated Power Cleaning does not improve quality. Epson also warns against using alcohol to clean the printer. You clarified that the 91% alcohol was on a towel under the head, rather than injected through the ink inlet. Even so, we cannot verify how a new cleaning fluid would interact with any remaining alcohol or this particular sublimation ink. Do not repeat the alcohol soak or mix cleaners.

Before buying a stronger cleaner, inspect only what is safely visible with the printer off: the yellow tank level and vent, accessible tubing for a kink or large air gap, and any obvious leakage or loose connection near the ink path. Do not move the carriage by force or reach into a powered printer. A capping station can look intact yet still fail to seal or draw ink; a technician may need to test its suction and the yellow supply path. If you find a leak, stop and arrange diagnosis. A cleaner will not fix an air leak or a mechanical supply fault.

BCH's Green cleaning solution is listed for sublimation ink, while its adapter guidance reserves the stronger Red cleaner for very severe clogs. The pattern supplied does not establish that Red is appropriate. The BCH ET-8550/ET-8500 adapter is listed for this model, but it is a tool for an invasive procedure, not a test or guaranteed repair. Its instructions warn that excessive pressure can permanently damage the head. We would not recommend forcing fluid through a resistant head, allowing fluid near electronics, or starting an adapter flush until the ink path and capping function have been assessed and chemical compatibility is clear. A professional diagnosis is the safer next step if those checks do not explain the missing yellow nozzles; only then should head-level service or replacement be considered.

Read Epson's Power Cleaning guidance [https://files.support.epson.com/docid/cpd5/cpd59879/source/printers/source/ink_functions/tasks/et8500_8550_l8160_l8180/power_cleaning_lcd_et8500_l8180.html] and BCH's ET-8550 adapter instructions [https://bchtechnologies.com/products/unclogging-adapter-for-epson-printhead-cleaning-et-8550-et-8500] before any further cleaning. BCH's Green solution details [https://bchtechnologies.com/products/triple-action-cleaning-solution-for-dye-pigment-sublimation-inks] are here. You can also search the BCH Technologies YouTube channel [https://youtube.com/@bchtechnologies] for ET-8550 yellow-channel troubleshooting and capping-station checks. If the supply and cap tests require disassembly, contact BCH about the current repair-service options for a sublimation-converted ET-8550 before shipping the printer.