JVC Model 200 service manual Electronic Module Tilt-up, ILA Back Focus

Chapter 3---Service Adjustments

Place the second DVM, from Step 3, across these terminals.

Adjust the Arc Lamp current with this pot.

Figure 3-4.Arc Lamp Power Supply aperture.

5.Multiply the results from Step 2 and Step 3 together (Bear in mind that the millivolt reading from Step 3 should be interpreted as amps, i.e. 1millivolt=1 amp).

6.The resulting power from Step 4 should equal 750 watts.

7.If the result is not 750 watts, adjust the trimmer pot (refer to Figure 3-4). CW=increase, CCW=decrease. If increasing, notice that the Arc Lamp voltage from Step 2 may decrease slightly. Adjust the trimmer pot until power is 750 watts. CAUTION! Do not adjust beyond 775 watts or damage to the equipment may occur.

3.3Electronic Module Tilt-up

1.Remove the rear cover (Section 4.2).

2.Release the clasp on the left side of the electronic module (turn CCW and pull out).

3.Pull out the release pin on the rear-right side of the electronic module to tilt it up. Tilt the electronic module up to a vertical position.

4.Ensure the holding pin locks the electronic module in place.

3.4ILA® Back Focus

The ILA® Back Focus adjustment moves the ILA®/Relay Lens/CRT assemblies together to adjust the focal length. This adjustment allows the zoom lens’ tracking to remain focused throughout the entire range. Use Focus test pattern to perform this adjustment for each color. This procedure performs the Green ILA® Back Focus.

For best results, perform ILA® Back Focus with 2 people. One person will watch the screen close-up and the other will move the ILA®/Relay Lens/CRT assemblies back and forth. The adjustment is factory-set but may need some touch-up in the field.

To adjust the ILA® Back Focus:

1.Remove the rear cover (Section 4.2).

2.Tilt the Electronic Module up (Section 3.3).

3.For this procedure, view Green. Hide Red and Blue.

Model 200 Service Manual 3-5