Epson C1100 series drum units can be reset and reused if the print quality is still acceptable. This is great news as a new drum unit is very expensive!
The radio frequency chip on your drum unit shuts the drum unit when it reaches the end of its fixed page life. If the print quality is still acceptable to you, you can reuse the drum by cleaning out the waste toner and then replacing the chip.
The chip will not fix any print defects, or improve print quality. It only resolves the “Replace Photocondcutor message" and allows you to continue to print.