D Board - Sony CPD-420GS Training Manual

D Board

(Power Supply)
The Power Supply, which is located on the D Board, operates very similar
to previous monitor chassis design such as the D1 chassis. This unit
incorporates the use of a switch mode power supply. It has both PWM
and RCC characteristics. The Power Supply has four modes of opera-
tion. Except for the AC power switch, three modes are controlled by
IC1001 (N Board). The modes of operation are 'Off', 'Active Off', 'Sus-
pend/Standby' and 'Active On'. These modes are related to the Power
Saving and Self Diagnosis functions. The Power supply provides all the
necessary operating voltages along with Horizontal Centering and CRT
Heater voltages.
(Deflection)
The Horizontal and Vertical deflection circuits along with Horizontal Cen-
tering, Size, Rotation and Tilt are located on the D Board. The N Board
provides these circuits with the necessary size, position and geometry
parameters as required by the different video timing conditions and user
adjustments. Impedance matching (S Caps) and Horizontal Linearity are
also performed in the Horizontal deflection circuit as required by the dif-
ferent video timing conditions.
7
(Convergence)
Both Static and Dynamic Convergence circuits are located on the D Board.
The N Board provides these circuits with the necessary geometry param-
eters as required by the different video timing conditions and user adjust-
ments. The convergence circuits provide two-dimensional (H and V) cor-
rection patterns that are applied to the convergence yoke.
(High Voltage)
T
he HV generation and regulation circuits are located on the D Board.
The N Board provides the HV circuits with the necessary drive param-
eters required by the different video timing conditions. The HV circuit
provides the CRT with Anode, Focus and Screen voltages required for
proper CRT operation.
The D98 chassis is also equipped with Dynamic Focus circuitry located
on the D Board. The Dynamic Focus circuit, controlled by the N Board,
provides the necessary focus control voltage for the outer edge areas of
the screen as required by the different video timing conditions.