Program For Epson L121: Adjustment

The adjustment program is technically a proprietary Epson tool. However, in many jurisdictions, resetting a counter on hardware you own is legal under "right to repair" laws (e.g., EU and some US states). Epson may refuse future service if they detect a reset (they can query the firmware log). But for personal home use, thousands of users have successfully revived their L121 printers this way.