JVC Model 200 service manual Scanning signal states, Front/Rear Floor/Ceil

Chapter 2---System Description

2.3.10 Scan Reversal Board

The Scan Reversal Board (SRB) is mounted vertically on the right side of the card cage.

The following functions are provided by the SRB:

•Reversal of scan in both horizontal and vertical axes

•Horizontal width adjustment for each color (R, G &B)

•Horizontal current feedback

•Scan failure detection for all six main (horizontal and vertical) deflection amplifiers

The Scan Reversal Board Input/Output diagram (Figure 2-16) and the list of inputs and outputs (Table 2-15) provide information for the technician to perform module level troubleshooting. Table 2-14 shows the signal states for modes of projector operation.

The SRB does not require any IIC bus interface.

Table 2-14.Scanning signal states

Mode of Operation	FRONT/REAR	FLOOR/CEIL
	line	line
Front and floor projection	Low	Low
Front and ceiling projection	Low	High
Rear and floor projection	High	Low
Rear and ceiling	High	High

Model 200 Service Manual 2-57