Unlike HP or Canon printers that use visible cartridges, Epson uses a piezoelectric print head system. During cleaning cycles, the printer flushes a small amount of ink into an internal "waste ink pad" (a sponge inside the base of the machine). The printer tracks exactly how much ink has been flushed. After approximately 15,000 to 20,000 pages, the counter hits its limit. The printer assumes the sponge is full and locks down permanently.
Modifying your printer voids the manufacturer’s warranty. Handling printer internals risks electric shock and ink spills. Proceed at your own risk. Always work in a ventilated area with protective gloves. epson t50 resetter