Panametrics CTF878, Service Manual

Page: 49 / 67

Model CTF878 Service Manual 39
Chapter 5.
5.1.3 Removing the Printed Circuit Board
Some of the maintenance procedures require removal of the printed circuit board. To accomplish this, refer to Figure
on page 43 and Figure 1-2 on page 11 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 41.
Otherwise, refer to Installing an Option Card on page 40.