Overall Block; A Board; Ma Or Mb Boards; Ca Or Cb Boards - Sony KV-13FM12 Training Manual

Overall Block

Overview
The BA-5 chassis is new for the 2000 model year. It is the first of the BA
type chassis to cover 13" to 32" models using the FD Trinitron tubes. In
order to accomplish this, parts common to all models are on one board,
the A board. The MA or MB board contain the video processing and
Syscon sections. If the set contains surround sound audio then it will
have a K board. CA or CB boards contain the CRT Drive and Velocity
Modulation. All 27" and above models contain a D board. Some 27" and
above sets contain P and B boards which plug into the MB board. These
boards are for PIP and a 3D Digital Comb Filter.

A Board

Power Supply
The A board contains sections that are common to all models. It contains
the standby and switching power supplies. The Standby supply is an
Energy Star complaint switching supply. It produces 7.5 volts to be used
by the MA AND MB board. The MA AND MB board contains a 5V Regu-
lator to power the System Control IC. The main switching supply pro-
duces +135 volts, Audio B+ and low voltage supplies. The low voltage
supplies are +12, +9 and +5 volts.
The A board contains a degaussing circuit which is activated by the DGC
line from System Control. This line controls a relay, which when acti-
vated, supplies 120 VAC to the degaussing coil.
Audio
The audio section on the A board contains the audio output amplifier.
There may also be a switching IC that selects the correct audio input if the
unit does not contain a K board. Any unit that features surround sound
audio or SRS will have a K board.
Video
The A board contains front and rear input jacks and the main tuner. 24"
inch and under sets will have a video input select switch on the A board.
In other models, the video switching will be handled by the YCJ on the MA
board.
5
Deflection
The horizontal, vertical and pincushion correction circuits are contained
on the A board. These circuits control the current through the yokes in
order to correctly scan the CRT. The FBT produces supply voltages for
the vertical output and creates high voltage, focus voltage and G2 screen
voltage. Pulses are monitored by the H protect circuit. If these pulses
become too large, they will activate the latch circuit which will shut down
the supply.

MA or MB Boards

The MA AND MB boards contain the YCJ and System Control circuits.
The MB board will be used on all 24" and under sets. All 27" and larger
sets will use the MA board. These boards use different YCJ and System
Control ICs. The different YCJ allows for more inputs and also controls
video switching in the larger sets. In addition, the larger sets contain a
different System Control IC that is utilized to produce a better OSD and
menu system.
In models that have the PIP function, a 2
added to the MA board. The P board creates the sub picture using the
nd
video from the 2 tuner.
The KV27FV16 contains a 3D Comb Filter that resides on the B board.
The B board plugs into the MA board similarly to the P board.

CA or CB Boards

All 24" and under sets will contain the CB board. The CB board includes
the CRT Drive and North/South Drive for tilt correction. The similar CA
board will be used on all 27" and over models.
VA or VB Boards (Not shown)
All sets contain a VA or VB board, which contains VM Drive.
D Board (Not shown)
Larger sets will contain a D board. This board contains Quadra-pole and
Dynamic Focus circuits necessary to produce a better picture on larger
screen size models.
nd
Tuner and a P board will be