Scantron OpScan 4ES Operator's Manual page 205

Operator's Guide
CAUTION: Watch for excess ink on the cartridge
that can soil your hands, clothes, or other
items.
3.
Using a clean swab, gently wipe the area of the
cartridge holder that contains the electrical
contacts.
CAUTION: Do not spray any substance directly
into or on the cartridge holder.
4.
Install the cartridge. Slide the cartridge into the
cartridge holder "feet first" then press the top of
the cartridge firmly into the cartridge holder until
you feel two clicks. This ensures that the cartridge
is fully seated.
Chapter : Transport Printer
Cleaning the Cartridge Holder
185