Chapter 4—Maintenance

Example: If the center brightness is 20 foot-candles, the ideal edge brightness should be 10 foot-candles.

CAUTION! Do not allow roll-off to be greater than 4:1 or damage to the Cold Mirror could result. Refer to Section 3.11 information on how to check roll-off.

3.In some cases it may also be necessary to adjust the vertical and horizontal orientation of the collimating lens to achieve maximum brightness.

CAUTION! This adjustment can be sensitive and should not be attempted unless all other measures have been tried first. To do this, loosen the three (3) mounting screws on the rear of the condenser lens mount (see Figure 4-6) and move the collimating lens to orient the hot-spot (brightest area) to the center of the screen.

4.5System Power Supply

The System Power Supply is located immediately forward of the electronics card cage.

To remove the system power supply (see Figure 4-4and Figure 4-5and Figure

4-7):

1.Unplug the projector. Allow at least one (1) minute for high voltage to bleed off before proceeding.

2.Remove the rear projector cover (Section 4.2).

3.Remove the two (2) screws from the Plexiglas cover over the terminal block (top of SPS, forward-Figure4-1) and remove cover.

4.Label and remove the arc lamp ignitor cables, J503 and J504, and the shield ground wire from the DC terminal block.

5.Remove the Plexiglas cover from the AC input terminal block located on the right side of the power supply (see Figure 4-7).

6.Ensure power is disconnected then remove the three (3) AC input wires from the AC terminal block:

Green (or Yellow/Green) left terminal (Ground).

White (or Blue) middle terminal (Neutral).

Black (or Brown) right terminal (Hot).

NOTE: Colors may be different, depending on country of use.

Model 330, 340SC, and 370SC Service Manual

4-11

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Image 124
JVC 370 SC, 330, 340 SC service manual System Power Supply, To remove the system power supply see -4and -5and Figure