High Voltage; Video Processing - Sony CPD-G400 Training Manual

Deflection Support Stages
Stage Parts
Dynamic IC1001
Focus
IC801
Q701-5,
IC503, Q706.
Pincushion IC1001
IC801
Q506, Q508-9
Convergence IC1001
IC801
IC701
IC702

High Voltage

The high voltage block uses a flyback transformer and some of the later
horizontal deflection circuits. This block's primary purpose is to develop
and maintain the high voltage for the final beam acceleration across the
picture tube bell. Two additional high voltages are also made from the
flyback T901. The static focus voltage is used for focus at the center of
the screen and the G2 voltage is necessary to accelerate the beam after
the focus grid slows down the electrons.

Video Processing

The video-processing block consists of an input switch, amplifier and out-
put stage. An on screen display IC003 is added to provide visual feed-
back about the monitor functions and features.
Function
Oscillator signal for beam location
Signal shaping
Horizontal dynamic focus amp.
Vertical dynamic focus amp.
Oscillator signal for beam location
Signal shaping
Amplifier and output driver
Oscillator signal for beam location
Signal shaping
Static convergence amplifier
Dynamic convergence amplifier
7
Video Processing Block
Stage Parts
Input Switch IC008
IC009
RGB Amp IC001
Output IC002
OSD IC1001
IC003
DAS Control
An external alignment computer controls many parts of the monitor's align-
ment. The alignment is achieved using a special computer to monitor
communications connection on the D board. The 4 pin internal jack con-
nects to the monitor's CPU IC1001.
• TXD – Transmits signal to DAS computer
• RXD – Receives signal from the DAS computer
• Stby +5V – Monitors power - Present when the monitor is ON.
• Gnd – Common ground.
A computer loaded with DAS software permits monitor adjustments by
changing the data stored in memory (IC005 not shown) via CPU IC1001.
The DAS software will permit the technician to change this memory data
which affects these stages:
DAS Control via CPU IC1001
Adjustment
CRT background and G2 level
H & V Position (centering)
H & V Size
Pincushion
Convergence
Function
RGB input switch
Sync input switch
Preamp of the input signal
Higher voltage amplifier
Selects OSD pattern based upon user
selection
Generates the OSD picture/graphic
Circuits used
IC001
IC001 Video signal positioning
IC801 Deflection size
IC801, Pin Output transistors
IC801, Conv Outputs