JVC 340 SC - Manual (Page 44)

Chapter 2—Functional Descriptions
2-32 Model 330. 340SC, and 370SC Service Manual
System Power Supply
Inputs Description
+48V Power for horizontal deflection
+15V Power for the analog section of the HDB
-15V Power for the analog section of the HDB
+5V Power for the digital devices on the HDB
GND Return for HDB
Interlocks and Protection
Input
None
Output
HSENSRED - Used to shut down the CRT beams in the event of horizontal sweep
failure.
HSENSGRN - Identical to HSENSERED.
HSENSBLU - Identical to HSENSERED.
Internal
+INLCK
Prevents the horizontal output section from being turned on when 1 or more
deflection coils not connected.
-INLCK
! Part of +INLCK circuit.
! Minimum Frequency on Oscillators and PLLs
! Ensures that there will be a sweep in both the horizontal and vertical
directions when the sync pulse disappears. This is for protection of the CRT
phosphor.
Vertical Deflection Board P/N 102521(VDB)
The Vertical Deflection Board plugs into the electronics card cage and is the second
board from the front in the card cage.
The following functions are provided by the VDB:
Drive main vertical deflection coils to provide vertical raster scan for
all three (3) CRTs.
Drive all correction coils to provide convergence and geometry
correction.
Scan failure detection for all six main deflection circuits.
Vertical size adjustment.
Vertical linearity adjustment.