JVC 330, 370 SC, 340 SC service manual Horizontal Deflection Board

Models: 340 SC 370 SC 330

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Horizontal Deflection Board

Chapter 2—Functional Descriptions

/Hx112

112 times the horizontal frequency for convergence and Z axis

 

correction address generator clocking. (TP 20)

/CORSTRT

Signal used to start the convergence and overlay address

 

generators during each horizontal sweep. (TP 4)

/FRAMEST

Indicates the beginning of a frame. Used in the SCB for

 

counting vertical frequency. (TP 5)

INTI

Indicates when input source signal is interlaced. (TP 2)

/VSYNCSC

Regenerated vertical sync signal, pulse shaped to 3 horizontal

 

lines in width. (TP 7)

/FIELD1

Low during field #1 of an interlaced input source. (TP 8)

/MAPST

Pulse signal to signal the overlay and correction address

 

generators to reset for a new frame. (TP 12)

 

 

 

 

I/O

Description

IICDATA

IIC data line. Bi-directional serial line for synchronous data

 

transfer between SCB and other circuit boards. See detailed

 

description for list of signals transferred and data direction.

 

 

 

 

 

Video Processor Board

Inputs

Description

SGSYNC

Stripped Green Sync is Sync-on-Green composite sync signal.

 

(TP 10)

HCSYNC

Horizontal/Composite Sync. (TP 9)

VSYNC

Vertical Sync used only for separate H and V sync. (TP 21)

 

 

 

 

Outputs

Description

DCRSTR

Pulse for DC restore timed to correspond to ST, BP, or TL.

 

(TP 1)

VIDBLNK

Signal for image blanking from adjustment counters. (TP 6)

/VSYNCSC

Vertical sync signal pulse for ILA bias sync. (TP 7)

 

 

 

 

 

Horizontal Deflection Board

Inputs

Description

/HVFLBCK

Signal representing horizontal flyback from the HDB. Used for

 

determining H phase. (TP 17)

 

 

 

 

Outputs

Description

/VFBST

Signal to start the vertical retrace. (TP 11)

/HSYNCRE

Selected HSYNC signal. (TP 14)

 

 

 

 

 

Vertical Deflection Board

Outputs

Description

/PCST

Signal to time the start of T/B pincushion and linearity

 

correction. (TP 31)

 

 

2-24

Model 330. 340SC, and 370SC Service Manual

Page 36
Image 36
JVC 330, 370 SC, 340 SC service manual Horizontal Deflection Board