Theory of OperationWFM90D and WFM91D ServiceManual 3-3
16

InputBoard

Ref
Var
Gain
ExtRef
AudioIn
Video
In
Video
Out
Front
Panel
Keys
Partof P
Rasterizer
and
Graphics
Vert Defl
Horiz
Defl
Instrument
Control

Bottom Board

P/O TopBoard

LCDDi splay

Board

RGB
P/O TopBoard
Partof PTiming
Subcarrier
Oscillator
Timing
SelVid
Backlight
Brightness
RGB
Sweep Trig
Fuse
Fuse
Battery
SyncSeparator
PowerSupply and
BatteryCharger
±8VDC
+5VDC
Vector
±8VDC
+5VDC
ControlDAC
(16analog
Outputs)
Audio
Headphone
NTSC(or PAL) Decoder
(Selfcontained subcarrier
regenerator)
Burst
Lock
Vectorscope
(Including
Øshifter)
Clamp
Video
Out
RGBfrom
Rasterizer
andGraphics
Video In
LPF
B--Y
Fsc
R--Y
DSync
Display
Brightnessand
View Adjust
2
RGB
Reclock
U2
Serialto Parallel
U3
Digitalto Analog
U4

SDI InterfaceBoard

DCIn 11--18 VDC
Figure3 -1: Simplified block diagram (serial numbers B020100 and above)