Hughes JVC 220, Service Manual

Page: 80 / 140

Chapter 3---Service Adjustments
every 500 hours of operation. This procedure is performed using a
DVM and a "clamp-on" type current meter such as AMPROBE
Model AC/DC 1000 or equivalent.
To perform the Arc Lamp Current Setting:
1. Verify that power is off to the projector, or turn power off with
the remote (it is not necessary for the circuit breaker to be off).
2. Place a DVM (set to read up to 200VDC) across the Arc Lamp
±
terminals ( refer to Figure 4-4 for DVM location ).
3. Turn projector power on at the remote and circuit breaker.
4. Place the "clamp-on" current meter around the hot lead (white)
that goes from the Ignitor to the Arc Lamp and measure the
current going to the lamp.
5. Multiply the results from the DVM and the "clamp-on" current
meter together to get lamp power. The resulting power should
be 900 watts.
Figure 3-4. Zoom view of ALPS aperture.
6. If the result is not 900 watts, adjust the current adjust pot on the
ALPS ( Figure 3-4 shows the current adjust pot locatlion within
the ALPS aperture. See Figure 4-4 for the aperture location ).
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 900 watts.
CAUTION! Make
adjustments in small increments and do not adjust beyond 920
watts or damage to the equipment may occur.
3.3 Electronic 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.
Model 220 Service Manual 3-5