Epson EPL-N3000 Reference Manual page 220

5. Insert the memory module into slot until the clip lock onto the
memory module. Make sure that the left slot (white) has a
module at all times.
Caution:
c
Do not force the memory module into the slot.
Be sure to insert the memory module facing the correct
way.
You should not remove any modules from the circuit
board. Otherwise, the printer will not work.
Installing Options
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