Hughes Jvc 220 Projector Service Manual

Chapter 4---Maintenance (Removal/Replacement) 
4.14   Scan Reversal PCB 
The Scan Reversal PCB is located on the right side of the 
Electronic Module. 
To remove the Scan Reversal PCB: 
1.   Remove the projector rear cover. 
 
Figure 4-10.   Scan Reversal PCB. 
2.   Disconnect 7 connectors; J52, J54, J64, J65, J66, J50 
(or J50A), and J100 (or J101). To remove, push in 
slightly, squeeze the tabs, then pull connector out. 
3.   Move all cables out of the way. 
4.   Remove the 4 pozidrive screws (Figure...

 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...

Chapter 4---Maintenance (Removal/Replacement) 
still connected to the CRT socket connector and the 
ground wire still connected from the CRT to the socket 
connector. This is because the Green socket connector 
is close to the rear of the projector and is easier to 
disconnect from the CRT after the CRT/Yoke Assembly 
is loose and is moved away from the rear. Be careful 
not to break any of these connections.  
Gently remove the CRT/Yoke Assembly by sliding it 
backward and upward as far as possible...

 Chapter 4---Maintenance (Removal/Replacement) 
 
Figure 4-12.  ILA® Assembly top view. The overlap screws shown are 
visible after the ILA® assembly is removed. 
4.   Loosen the two wingnuts at the top of the appropriate 
ILA® assembly (Figure 4-12). 
5.   Slide the spring clip at the top of the ILA® assembly 
backward (Figure 4-12). This will free the ILA® 
assembly. 
6.   Grasp the ILA®  assembly by its housing and slide it 
out.  
7.   Replace the ILA® in the reverse order from above. 
8.   Recheck...

Chapter 4---Maintenance (Removal/Replacement) 
4.   Loosen the CRT Lens Stopper Ring (the thin collar just 
in front of the CRT Holder knurled ring-Figure 4-11) 
and slide it off the back of the Relay Lens. 
5.   Loosen the wing nut on top of the Relay Lens mount 
(the bracket at the rear of the Relay Lens). 
6.   Remove the 2 long hex bolts at the front of the Relay 
Lens (shown in Figure 4-12). 
7.   Remove the 2 hex bolts at the rear of the Relay Lens 
(these bolts are level with the bottom of the...

 Chapter 4---Maintenance (Removal/Replacement) 
NOTE: When changing from a zoom to a fixed lens, or vice 
versa, the ILA® Back Focus (Section 3.4) may need 
readjustment. 
4.19   Prism Assembly 
CAUTION! The removal of the Prism Assembly 
requires removing the Dichroic Mirror Assembly (X-Plate). In most 
cases this necessitates an optical realignment. HJT does not 
recommend performing this replacement in the field. Optical 
alignment is critical and requires projector power to be on. This 
results in an...

Chapter 4---Maintenance (Removal/Replacement) 
8.   Remove the Rollbar Bracket that was holding up the 
left side of the Rollbar assembly. 
9.   Remove the 3 ILA® asssemblies (Section 4.15). 
 
Figure 4-14.   Dichroic Mirror Assembly. 
4-24  Model 220 Service Manual  

 Chapter 4---Maintenance (Removal/Replacement) 
 
Figure 4-15.   Prism Assembly mount. 
10. Remove the remaining three hex bolts from the rear of 
the Prism assembly. These screws are located in the 
cavities where the ILA® assemblies were removed (see 
Figure 4-15). 
11. The Prism is now free to be removed. 
CAUTION! The Prism assembly is 
heavy (about 70 lbs). Use two people to lift it out of the 
projector. 
12. Replace the Prism assembly in the reverse order. 
Model 220 Service Manual  4-25  

Chapter 4---Maintenance (Removal/Replacement) 
4-26  Model 220 Service Manual 
  

Chapter 5---Troubleshooting 
5.0  Troubleshooting 
Contents 
5.1   Status LEDs........................................................................\
.....5-1 
5.2   Error Codes........................................................................\
......5-4 
5.3   Troubleshooting Guide.............................................................5-6 
 
5.1   Status LEDs 
The illustrations below indicate where various LEDs are located that ind\
icate 
proper or improper operation of the System...