GE CTF878, User & Service Manual

Page: 55 / 72

Parts Replacement 5-3
February 2009
Removing the Printed
Circuit Board
Some of the maintenance procedures require removal of the printed
circuit board. To accomplish this, refer to Figure 5-1 on page 5-9 and
Figure 5-2 on page 5-10 while completing the following tasks:
1.
Remove the main power to the electronics console.
!WARNING!
The main power to the CTF878 must be disconnected
before proceeding.
2.
Open the electronics console. Remove the two mounting screws
and lift the clear plastic shroud out of the electronics console.
Remove the five mounting screws and lift the main aluminum
shroud out of the electronics console.
3.
Disconnect the main power leads from terminal block
TB1
on the
printed circuit board. Remove the electrical connections from all
installed option cards and terminal blocks. Disconnect the
twisted-pair backlight cable from connector
J6
, the two
striped-ribbon keyboard cables from connector
J5
, and the
white-ribbon display cable from connector
J7
.
4.
Using a Phillips screwdriver and a 3/8 inch nutdriver or open-end
wrench, remove the three mounting screws (just left of center) and
the five standoffs along the sides of the main circuit board.
5.
While supporting the printed circuit board, remove the two
standoffs along the bottom edge of the printed circuit board.
6.
Carefully lift the printed circuit board out of the enclosure.
Caution!
During this procedure, be very careful not to damage the
upright components along the top edge of the printed
circuit board. Severe or repeated bending of these
components will break their leads.
7.
The printed circuit board is now free and may be removed to a
clean work area.
If the printed circuit board is being replaced, proceed to the section
Installing the Printed Circuit Board on page 5-5. Otherwise, refer to
Installing an Option Card on page 5-4.