Do not dismount or mount printed–circuit boards unless you
have received maintenance and safety training.
When opening the cabinet and replacing a printed–circuit
board, be careful not to touch the high–voltage circuits
(marked and fitted with an insulating cover). Touching
directly the high–voltage circuits gives you a shock hazard.
When replacing a printed–circuit board, note the following:
1 When dismounting the printed–circuit board, be careful not
to touch semiconductor devices on the board by hand or not
to allow these devices to touch other parts.
2 Check that the settings for the new printed–circuit board are
3 After replacement, make adjustments, if necessary, for the
printed–circuit board correctly.
4 Cables removed during replacement must be connected as
they were connected previously. If there is a possibility that
the connection points of cables will be confusing, note down
the connection points before removing the cables.
5 Before replacing the printed–circuit board, turn off the
power to the control unit.