Troubleshooting The Ra-4A Chassis; Overview - Sony KDP-57XBR2 Training Manual

1. Features
Chapter 13 - Troubleshooting the RA-4A Chassis

Overview

The RA-4A chassis shares many of the circuit designs with its predecessor, the RA-4. It is still reserved for use
in the high-end XBR series, which includes the KP53XBR300 and the KP61XBR300. Its greatest feature was
the introduction of a "high definition ready" television utilizing a 4:3 screen aspect ratio. Since most of the media
being broadcast is still in this format, it was appealing to those who wished to be able to view HDTV if they could
acquire it. It also allowed the viewing of DVD movies in the "anamorphic" state whereby all 480 scan lines could
be utilized in the active video area while watching a letterbox version and would take advantage of the new 480
progressive DVD players entering the market. This would involve a feature known as "16:9 compressed mode".
Vertical scan would be reduced to simulate a 16:9 viewing area on the 4:3 screen.
Since the unit now qualified as "high definition ready", the horizontal deflection circuits underwent some changes
to allow it to operate at 33.4KHZ in addition to 31.5KHZ in order to display 1080i. The video 5 input allowed for
either RGB or component video from a HD source. Although video 4 provides for component input, it will not
accept the 1080i format. Any 1180i format signals received will be directly routed to the video processor. The HD
video source is unavailable to the multi-image drive circuitry and cannot be viewed in the picture & picture mode.
This chassis is unable to process 720p.
Other features included the addition of "V Chip" technology for greater parental control. Due to the ability to
generate three formats (4:3, 16:9 compressed, and 1080i), there are three NVM ICs on the BD board to store
registration adjustment data. The 3D comb filter has been moved from the A board to the BA board, which
mounts to the A board and also contains the A/D converter
Since the power supply and deflection circuits are virtually identical with the RA-4 chassis, Chapters 8, 9, 10, and
11 in this manual will provide the necessary information to service these circuits should the need arise. The
video path is similar to the RA-4 but has enough differences to warrant different approaches to isolate video
problems.
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