3.2.3 I will look into the wiper, eventually dirty cap and forign matter adhering to the print head. I will use windex and polyalcohol and lot of patience while performing under printhead cleaning. (if possible modus Entlich) ??
I experienced that cranking the printer up the printhead doesnt travel to the left. In old epson printers you could release the printhead by starting the printer and then disconnect the power befor the printhead travelled back to the cap station.
So I made a Nozzle check and disconnected the main power and the printhead was released. But not much space down there.
Sounds good.
Here is a summary of the other problems for the P900, aside from a nozzle clog, and some information on how to differentiate them. This is from online, so I cannot attest to its complete accuracy, yet it sounds about right. This is a bit beyond my own knowledge, yet it was helpful to me since I also have a P900. The only other factor not often discussed is OEM inks versus compatible inks. Experience from others indicates that OEM ink is better at preventing clogs and clearing them when they do occur.
I hope you get it solved.
John Wheeler
Epson P900 Nozzle Check Issues - Beyond Simple Clogs
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1. Ink Cartridge / Ink Supply
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- Empty or very low cartridge (even if printer reports ink remaining).
- Defective chip or sensor causing incorrect ink status.
- Improperly seated cartridge preventing ink flow.
2. Ink Lines and Dampers
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- Air bubbles trapped in ink lines (common after cartridge changes or long idle times).
- Partially blocked damper/filter reducing flow.
- Collapsed or kinked ink line preventing ink delivery.
3. Capping and Cleaning Station
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- Capping station misalignment (head not sealing properly when parked).
- Dirty or dried wiper blade smearing instead of cleaning.
- Pump failure (weak suction or cracked tubing).
- Cap pad contamination preventing proper suction.
4. Environmental & Usage Factors
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- Printer left idle for long periods, ink drying at nozzle plate.
- Low humidity (<40%) accelerating drying of nozzles.
- Frequent short prints without maintenance allowing sediment/micro-bubbles.
5. Electronics & Print Head Issues
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- Electrical failure in nozzle bank (driver circuitry failure).
- Physical damage (scratched or delaminated nozzle plate).
- Head overheating from repeated purges damaging piezo elements.
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Summary - How to Differentiate Causes
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- Nozzles reappear intermittently after cleaning/flushing → Air or drying issue.
- Full channel always blank → Damper, pump, or electrical failure.
- Patchy pattern that changes each test → Air bubbles or capping/wiping issues.
- Identical missing spots each time → True clogs or permanently dead nozzle rows.
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In my view - QTR is not controlling the spinning of the wheels. It is the very central control of ignition and valves.
