40 And 46-Inch S Line Models; Backlight Power; Power Supply; 32" Xbr And 40D3000 Models - Sony KDL-26S3000 Training Manual

40 and 46-inch S Line Models

In Figure 1-2 it is seen that most of the circuits found in the 26/32" models
is the same. Therefore, only the differences will be explained here.

Backlight Power

Separate circuits are used to supply high voltage to the backlight lamps.
These circuits only generate the high voltage needed. Balancer circuit
boards are mounted on the panel to distribute the high voltage and monitor
the current level to each lamp.
The 40" model uses a single D1 board to generate high voltage of
approxiamtely 4.5 to 5KV. The 46" however, requires the use of 2 high
voltage boards due to the longer fluorescent tubes. In this case a D1 and
D2 board is used to supply voltage to both ends of the fluorescent lamps.
This is important to remember when troubleshooting a lamp protection
shutdown problem. If one board fails you will notice that one side of the
screen is lighter that the other before the unit shuts down. The side that is
darker indicates which board is at fault.
IMPORTANT: Even though the 40 and 46" models both use a D1 board,
they are not interchangeable. The D1 board part numbers are different for
the 40 and 46".

Power Supply

A G3 board is used and uses a Power Factor Control circuit to generate
the 390VDC required by the D1 and D2 circuits. The on-board protect
circuits are slightly more sophisticated than the G1D and G1H boards but
the end result is to stop the power supply if certain over voltage and current
conditions arise. These items will be discussed later in this chapter.
CTV-41
Chapter 1 - Features and Circuit Descriptions

32" XBR and 40D3000 Models

All of the circuitry in these models are the same as their respective S
series models except for the addition of the BH and U2 boards as
illustrated in Figures 1-3 and 1-4. The circuitry on the BH board captures
the 60HZ frame rate video exiting BU1 board, analyzes the difference
between adjacent fields and generates additional fields in between to
double the frame rate to 120HZ. The end result is a dramatic reduction of
the smearing or "comet tailing" that is inherent to LCD displays during fast
moving video content.
The front video input U2 board provides an additional HDMI input not
found on the S series models. One analog component input was removed
to accommodate the additional HDMI so only HDMI and composite video
are accepted at these inputs.
6