Chapter 2—Functional Descriptions
Model 330, 340SC and 370SC Service Model
2-15
The card cage is hinged in the rear to allow it to be folded backward for access to
the CRT housing (when folding the card cage backward be sure that nothing is
plugged into the rear electronic jacks or the plugs could be severely damaged).
During normal operation, the card cage should be in its upright position to ensure
proper cooling of the CRT enclosure.
A holddown screw is provided to secure the card cage and prevent it from rotating
backward during shipping or when the projector is mounted in an upward-
pointing position. The holddown screw is located on the lower, front, right corner
of the card cage.
The rear panel of the card cage provides mounting for the projector controls. The
VPB, which receives all image and sync inputs, is secured to the rear panel by
four screws. The RS-232 control connectors and the IR receiver and repeater
inputs as well as the LED dot matrix status display are located on the lower left of
the rear panel. The projector model and serial numbers are also found on the rear
panel.
2.6 Circuit
Boards
The Model 330, 340SC and 370SC projectors have a total of twelve (12)
accessible circuit boards. Seven (7) boards are located within the card cage
(Figure 2-9) and five (5) are located outside the card cage (Table 2-2).
Table 2-2
Circuit Boards Outside Card Cage
No.
Description
330
340SC
370SC
1
Ignitor
102083
102207
104475
3
Video Amp Boards (VABS)
103567
103567
103567
1
Backplane
100571
100571
100571
Each circuit board can be replaced individually except the Backplane board and
the PLL. The PLL is replaced with the RTG as a unit. The Ignitor was previously
described in Section 2.4.2. The circuit boards covered in this Section are listed in
Table 2-3.
Table 2-3
Circuit Boards
Page
Circuit Board
P/N
2-18
Raster Timing Generator
(RTG)
100568
and PLL
2-26
Horizontal Deflection Board
(HDB)
102523
2-34
Vertical Deflection Board
(VDB)
102521
2-44
Video Processor Board
and optional Decoder Board
(VPB)
104672
2-55
Video Amplifier Board
(VAB)
103567
2-58
System Controller Board
(SCB)
104668
2-70
Backplane Board
100571
