3
1. Remove the unit front cover as
described in the previous pro-
cedure. Remove two ribbon
cables from the board.

<Installing the PDB1D board>

3. Remove six ribbon cables
from the board. At this
time, mark the ribbon
cables so that you can
identify each of them and
re-connect them correctly
later.
2. Remove eight fixing screws
on the rack mount hardware,
and remove the rack mount
hardware. Do not remove any
screws or hardware other than
those shown in the picture.
Remove twelve screws on the
left side cover, then remove
it. Note that the screws for the
rack mount hardware are dif-
ferent from the screws on the
side cover.
4. Remove the PDB1D board. At
this time, care should be taken
so that the board will not catch
the ribbon cable.
After replacing it with a new
board, follow the steps de-
scribed previously to re-install
the ribbon cables, side cover,
rack mount hardware, and
front cover.