Overall Block; N Board; A Board; H Board - Sony CPD-420GS Training Manual

Overall Block

N Board

The N Board is mounted to the D Board via connectors CN1001 and
CN801. The Microprocessor IC1001, EEPROM IC1005 and the DSP
(Digital Signal Processor) IC1002 are located on the N board. IC1001
receives control inputs from the front panel buttons (H board) and the
front and rear video inputs via the A board. IC1001 responds to the Tim-
ing and Sync parameters of the video inputs. IC1001 communicates with
IC1005 via the I 2 C bus. IC1005 contains the operation, set up, factory
preset and user preset data and is utilized by IC1001 to control the moni-
tor circuits and to match the operating parameters to the input signals.
IC1001 also controls IC1002 via the I
necessary timing and sync parameters.
IC1001 directly controls Input switching, Rotation, H. Cent, H Lin Bal,
Degauss, Power Shutdown, Heaters, Remote On/Off and S Caps (Im-
pedance Matching). IC1001 controls the Power Save Function, OSD (On
Screen Display) and RGB DRIVE (A board). IC1001 also provides com-
munication with DAS (Digital Alignment Software), CATS (Color Adjust-
ment Tool for Service) and the DDC (Display Data Channel).
IC1002 outputs Deflection Drive, Convergence and Geometry Correction
Waveforms to their respective circuits located on the D board.
2
C bus and provides IC1002 with the
5

A Board

The main function of the A Board is to receive incoming video signals and
process them into RGB video drives for the CRT. Video signals can be
received either from the conventional 15 D-sub connector or via an addi-
tional 15 D-sub female connector input located on the front of the monitor.
The purpose of this second input is to allow easy hookup to a laptop
computer (video cable provided).
The A Board circuitry buffers the Sync timing signals and provides OSD
video. The Timing Analysis for the ASC (Auto Size Center) function and
the Analog to Digital conversion for the Color Restoration function are
also processed. Additional functions include the DDC information to the
DDC equipped host computer and all CRT cathode operating voltages
such as Heater, G2 (Screen) and Focus are either processed or passed
to the CRT.

H Board

The User controls are located on the front bezel assembly of the monitor
and provide the user with control of various monitor operations and func-
tions. The LED provides the user with feedback as to the Power Saving
and Failure condition of the monitor.