Chapter 4—Maintenance
4-20
Model 330. 340SC, 370SC Service Manual
7.
Perform a CRT mechanical focus adjustment (Section 3.7) and yoke
alignment (Section 3.2) after yoke replacement.
4.10 High Voltage Power Supply (HVPS)
The HVPS is located on the left side of the projector next to the CRT housing
assembly.
To remove the HVPS:
1.
Unplug the projector. Wait at least a minute before proceeding for the high
voltage to bleed off.
2.
Run all three (3) CRTs all the way forward using the Z axis focus rods at
the rear of the CRT assembly (Photo 4-6).
3.
Remove all three (3) video amplifier boards (refer to Section 4.8 and either
Figure 4-4 or Figure 4-5).
4.
Remove the System Power Supply (see Section 4.5).
5.
Remove the System Power Supply mounting plate (covers High Voltage
Power Supply).
6.
Inside the CRT housing on the left side, disconnect all three (3) CRT
anode cables from the bulkhead connectors. As an added precaution, short
the anode leads to the High Voltage Chassis ground to bleed off any
residual charges. Slide the anode wire connectors off their mounting
brackets.
7.
In the bottom rear of the CRT housing, cut the tie wraps holding the HV,
G2, and focus cables.
8.
Carefully slide all G2, and focus cables out of the CRT housing.
9.
Remove the top connector (power control) at the rear of the HVPS.
10.
Loosen and release the five (5) captive screws at the base of the HVPS:
Two (2) screws are located forward.
One (1) screw on top.
Two (2) screws at the rear.
11.
Remove the HVPS.
12.
Replace the HVPS in the reverse order.
13.
Perform a CRT mechanical focus adjustment, yoke alignment, G2
adjustment, and electronic focus adjustment after HVPS replacement
(Sections 3.7, 3.2, 3.10, and 3.8).
NOTE:
When replacing the HVPS, ensure that the wires are routed to the
proper color and that the wires are neatly placed in the bottom of the CRT
housing.
