Epson EPL-6200 Reference Manual page 335

c
6. Carefully insert the developer cartridge into the new
photoconductor unit's casing until it clicks into place, making
sure that the pins on both sides of the developer cartridge are
aligned with the grooves on the casing.
318
Replacing Consumable Products
Caution:
Never touch the photoconductor unit's light-sensitive drum.
Otherwise, print quality may decline.