HP LaserJet 4610n - Manual (Page 209)

10. Align the formatter board in the tracks at the top and bottom of the slot, and then slide
the board back into the printer. Replace and tighten the eight screws removed in step 4.
11. Reconnect the power cable and interface cables, and turn the printer on.
12. If you installed a memory DIMM, go to Enabling memory .
To install a flash firmware card
ENWW Installing memory 197