Samsung ML-2151N-XBH - Manual (Page 211)

P ROGRAMME I NSTALLING P RINTER O PTIONS F.4
3 Locate the PS DIMM slot (the upper slot) and the memory
DIMM slot (the lower slot) on the control board. They are
not interchangeable.
To install the PS DIMM, continue with Step 4.
To install the memory DIMM, go to Step 5.
4 Hold the PS DIMM so that the notch and the connection
point are aligned with the slot as shown, and insert it all the
way into the upper slot labelled “ROM DIMM” at a 90
degrees angle.
5 Hold the memory DIMM so that the notch and the
connection point are aligned with the slot as shown, and
insert it all the way into the lower slot labelled “RAM DIMM”
at a 90 degrees angle.
PS DIMM
Memory DIMM