JVC 250 service manual Video Input Cards VICs

Chapter 5---Electronics

NOTE: For the Green CRT/Yoke Assembly only, it is best to perform Step 10 with the CRT socket connector still connected to the Green CRT and the ground wire still connected from the CRT to the socket connector. Because the Green CRT socket connector is close to the rear of the projector, it is easier to disconnect the socket connector from the CRT after the CRT/Yoke Assembly is loose and moved away from the rear of the projector. Be careful not to break any of these connections.

CAUTION! Use extreme caution to avoid bumping

the CRT/Yoke Assembly while removing it (see Warning at the beginning of this procedure).

11.After removing the CRT/Yoke Assembly, carefully disconnect the CRT socket connector and the ground wire that connects the CRT to the socket connector.

NOTE: It may be helpful to have another person assisting for step 9. One person can disconnect the CRT socket connector and ground wire, while the other person holds the CRT/Yoke Assembly firmly.

12.After verifying that all cables are out of the way, remove the CRT/Yoke Assembly from the projector.

13.Reinstall the CRT/Yoke Assembly in the reverse order.

NOTE: When reinstalling the CRT/Yoke Assembly, plug the CRT ground wire into the CRT Socket Connector first, then partially plug the Green socket connector into the CRT. Inserting the CRT fully into the socket connector will be easier when the CRT is completely installed.

14.Perform a CRT Mechanical focus adjustment and CRT Rotation after replacing the CRT/Yoke Assembly. Because replacing the CRT/Yoke Assembly can disturb other focus adjustments, check the CRT Mechanical Focus on the other two colors to verify that they are still correct.

15.Check the on-screen horizontal size and adjust the Horizontal Size Adjustment Coils on the Scan Reversal PCB if necessary.

5.11Video Input Cards (VICs)

The VIC is the interface between the input source and the projector. Several input source format are accepted such as separate RGBHV, Composite, YPbPr, and S- Video.

The Model 250 accepts six different VICs;

!Wide Bandwidth RGBHV (Standard)

!Graphics Enhancer Plus RGBHV(Standard)

!4-Input (Quad) RGBHV (Optional)

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