Block Diagram - Sony WRR-800A Service Manual

Outline
The WRR-800A consists of the following boards and tuner unit:
Board name
MB-786 board
CN-1598 board
VR-245 board
RE-157 board
Tuner Unit
The tuner unit consists of the RF board and the DP board.
Tuner unit works as a PLL synthesizer diversity tuner, and its power voltage (DC +9V) is supplied from the CN-1598
board through the MB-786 board.
The RF (radio frequency) signals are input from both antenna A and antenna B, and the audio signal is output to the MB-
786 board through the CN-1598 board. The RF board is composed of RF block, audio block, CPU block and voltage
regulator.
The DP board is composed of display block and the operation block.
Power Supply Block
The DC +9 V from the AC power adapter is input to the MB-786 board, it is converted up to ± 15 V with DC-DC converter
(IC1001), then output as ± 12 V from the voltage regulator (IC1004/IC1005). Generated ± 12 V are used for the power of
audio output amplifier (IC1101) on the MB-786 board. Also, to generate +9 V, converted +15 V is input to the voltage
regulator (IC1006), then obtained +9 V is supplied to the tuner unit.
Audio Block
The audio signal (AF) output from the tuner unit is input to the MB-786 board through the CN-1598 board. Signals is then
output from the output connector (J1101) after passing through the filter amplifier (IC1101), output amplifier (IC1101) and
audio muting circuit.
MB-786 Board
The power supply block and audio signal output block are mounted on this board. This board consists of the DC-DC
converter circuits (DC+9 V to ± 15 V), voltage regulator circuits (± 15 V to ± 12 V), audio output circuit and audio signal
muting circuit.
CN-1586 Board
This board functions as a relay board for signal buffering between the tuner unit and MB-786 board.
VR-245 Board
This board is functioned as an audio output adjustment.
RE-157 Board
This board is functioned as voltage regulator for the tuner unit.
WRR-800A
SECTION 5

BLOCK DIAGRAM

Ref. No.
1000 to 1200 series
110, 1100, 1300, 1700, 2000 to 2400 series
1200 series
1000, 1200 series
5-1