S Degauss Coil; Logic. Board Planar Strips; Removal; Replacement 4-\0 - IBM 3279 2A Maintenance Information

3279 MIM
4.8.5 Degauss Coil
To remove and replace the degauss coil, go to
section 4.8.3 "CRT and Coil Assembly". For
removal, follow 'Removal' steps 1 through 13. For
replacement, follow 'Replacement', steps 5 through
23 omitting step 13.
Display adjustments should not be affected, but
refer to Chapter 5 if necessary. Reinstall all safety
covers and close the logic gate.
4.9 Logic BOl!rd Planar Strips
4.9.1 Removal
1. Switch power off and remove the mainline cable
from the power socket.
2. Remove the rear cover (see section 4.3)
3. Disconnect all connectors and note their
locations.
4. Remove the logic cards.
5. Remove the two diagonally opposite screws (top
right and bottom left) that attach each rear
planar strip holder to the logic gate.
6. Remove the rear holders and planar strips.
4.9.2 Replacement
1. Feed the cables that plug into the strips through
the gap at the right-hand side of the logic gate
(as viewed from the rear), It is easier if the
shrouds are removed; replace them afterwards.
2. Ensure that the card-locating shoulders on the
strip holders are positioned the correct way
round (see Figure 4-9).
3. Insert the planar strips and rear holders in
approximately their correct positions. Insert, but
do not tighten, the strip-securing screws.
4. Plug all the logic cards into the gate and clip
them in position.
5. Close the logic gate so that the enclosure
positions it at the correct height, then tighten
the strip-securing screws.
6. Open the logic gate. Reinstall all connectors
(pass the keyboard cable through the gap at the
right -hand side of the logic gate as viewed from
the rear).
Chapter 4. Removal and Replacement Procedures 4-10
Shoulders
Note: Shoulders should be to the left and arrows pointing
up for both card side and pin side of holders when viewed
from the appropriate side.
Figure 4-9. Planar Strip Holders