The Ra-5A Chassis; Troubleshooting The Ra-5A Chassis; Overview - Sony KDP-57XBR2 Training Manual

1. Features
Chapter 15 - Troubleshooting the RA-5A Chassis

Overview

The RA-5A chassis is Sony's first high definition, 16:9 aspect ratio, rear projection television to incorporate a DTV
tuner and decoder as an integrated part of the chassis. This tuner/decoder assembly is known as the "Q Box". It
TM
contains a HDTV tuner, MPEG2 and Digital Dolby® decoding circuits, along with the DRC (Digital Reality
TM
Creator) and the MID (Multi-image Driver). Video inputs 5 and 6 also allow HDTV signal sources from external
devices such as satellite or third party HD receivers to be hooked up to the unit.
The set is able to receive all current forms of analog and HDTV signals, including 720P. The horizontal deflection
stage is designed to run at a fixed frequency of 33.75KHZ. All non-HD incoming video signals are line doubled by
TM TM
the DRC to 960i. Since 960i only requires a scan rate of 31.5KHZ, the MID circuits will place the 960 inter-
laced lines inside of the fixed 1080i scan rate. The remaining 120 unused lines (60 above and 60 below) will be
TM
moved into the over-scan area by increasing vertical size. 480p sources are converted to 960i by the MID
TM
circuit and inserted into the 1080i fields in the same manner. 720p is converted to 1080i by the MID .
The power supply is of a new design Power supplies would be a better term to use, as there are four of them: A
standby, primary, secondary and high voltage control. A new troubleshooting approach will be necessary since a
failure in the primary supply will keep the secondary supply from operating. This will be covered in Chapter 16.
IEEE1394 (ILINK ®) ports are included at the rear with 200Mb throughput. The Q-Box also contains a slot for a
memory stick to provide firmware upgrades for the decoder circuits if needed. The CRT driver ICs are a new
design, extending the bandwidth to 32MHZ in order to reproduce 1080i video resolutions with more detail.
For a more detailed description of the features and circuits, refer to the C29P12 training manual (P/N C29P120901).
67