Hughes JVC 220, Service Manual

Page: 112 / 140

Chapter 4---Maintenance (Removal/Replacement)
Three CRT/Yoke Assemblies are located in the CRT Assembly
area below the card cage. To remove a CRT/Yoke Assembly
(
refer to Figure 4-11 ):
Figure 4-11. View of CRTs, Relay lenses and ILA
®
Assemblies.
1. Remove front and rear covers ( Section 4.2 ).
2. Tilt the Electronic Module up and lock it in place
( Section 3-3 ).
3. Remove the two pozidrive screws from the top of the
High Voltage Power Supply (HVPS) cover ( Figure 4-5)
and loosen the one screw at the bottom of the cover
(do not remove the bottom screw-it is difficult to
replace-the HVPS will slide up and over it).
4. Remove the CRT anode cable (for the CRT that is to
be replaced) from the HVPS.
5. Disconnect the Yoke plug and cable harness from the
Scan Reversal PCB for the appropriate CRT ( see
Figure 3-7 ).
6. Remove the wires from the cable clamp for the
CRT/Yoke Assembly that is being removed.
7. Loosen the CRT Holder Ring ( knurled knob in Figure
3-5 ). NOTE: The CRT Holder Ring should be only
hand-tight. If it cannot be removed by hand only, a
flathead screwdriver can be used in the slots on the
CRT Holder Ring to help loosen it.
Do not use a tool of
any kind to tighten this ring-it should be hand tight only.
8.
CAUTION!
For the Green CRT/Yoke Assembly
only, this step is best performed with the Green CRT
Model 220 Service Manual 4-19