Sy27-2510-6 (1/81 ); High-Voltage Power Supply; Fuses; Card/Connector Removal And Replacement Procedures - IBM 3278 Series Maintenance Information

4. WT except Canada: Disconnect the two wires
(two screws) leading from the ferro terminal strip
to the prime power assembly. Note where the
leads are connected for reinstallation.
5. EMEA ferrotransformer only: Remove the screw
fastening the ground wire (green/yellow) from
the side of the prime power assembly.
6.
Disconnect the two cable
conn~ctors
and slip-on
connector from the ferrotransformer to the low-
voltage assembly.
7. Remove the outer mounting screw holding the
ferro to the frame and loosen the inner screw.
8. Slide the transformer out of the frame.
9. Reinstall in the reverse sequence.
10. Check the +44 V supply using procedure 5.4.
6.2.5 High-Voltage Power Supply
1. Using an insulated jumper wire, ground the CRT
anode terminal to discharge static charge.
Carefully disconnect the CRT anode lead;
static charge may be present.
2. Disconnect the input cable at the lower edge of
the high-voltage assembly (see Figure 4-4).
3. Open the logic gate by loosening the front
mounting screw located in back of the high-
voltage supply support shield.
4. Remove the high-voltage supply mounting screw
located on the back of the high-voltage support
shield.
5. Slide the power supply out of the support shield.
6. Reinstall in the reverse sequence. Ensure that
the anode lead is firmly seated on the CRT bell.
6.2.6 Fuses
1. Fuses are located near the line-voltage cord
socket and under the low-voltage shield.
6.2.7 Card/Connector Removal and Replacement
Procedures. All cards and internal connectors (except
the CRT socket) have mechanical locking devices.
SY27-2510-6
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