Sony DAV-S300 (serv.man2) Service Manual ▷ View online
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DAV-S300
(HCD-S300)
Troubleshooting guide
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Contents
1. Troubleshooting at Start-up --------------------------------------------------------------- 3
(1) Stand-by Mode
(a) Voltage supply for microcomputer
(b) Output of Reset signal
(c) Setting of Stand-by Mode
(2) Operation mode ----------------------------------------------------------------------------- 4
(a) Detection of Wake-up key
(b) Display of Fluorescent tube
(c) Start-up of DVD circuit
(d) Release of Sound Mute
(e) Setting of tray position ------------------------------------------------------------------ 5
(f) Setting of OP block position
(g)Setting of Tilt default ---------------------------------------------------------------------- 6
(h) Image output
(i) Focus search
2. Troubleshooting in Test mode ------------------------------------------------------------ 8
(1) Display of emergency history
(2) Syscon Diagnosis
(3) Video Output Circuit
3. Miscellaneous -------------------------------------------------------------------------------- 9
(1) Lens cleaning
(2) Compatibility with NEW and OLD board
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1. Troubleshooting at Start-up
(1) Stand-by Mode
(a) Voltage supply for microcomputer
5.6V for microcomputer is output from power circuit and supplied to audio micro
computer (IC903) when connecting AC plug to an outlet.
(b) Output of Reset signal
Reset signal from reset IC(IC902) lets audio micro computer (IC903) start up.
(c) Setting of Stand-by Mode
Power LED illuminates in red when audio microcomputer starts up normally and moves in
Stand-by Mode. Audio microcomputer detects key / remote input and performs LCD control.
The system changes to Operation Mode when Wake-up input (key/ remote) is recognized.
(Repair Know-how)
In case that audio microcomputer doesn’t start up, confirm the fuse (F901) on Power
board. Also, confirm input of reset signal (IC903 12 pin).
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(2) Operation Mode
(a) Detection of Wake-up key
Audio microcomputer (IC903) detects a kind of key when a key on the main body and
remote is pressed. If Wake-up key such as Power button is pressed, the system changes to
Operation Mode.
The color of Power LED changes from red to green when the system turns into Operation
Mode. Also, Power ON terminal of audio microcomputer (IC903 78pin) changes from L to H.
Then each power supply voltage is output from Power board.
(Repair Know-how) Color of LED
In case that the color of LED doesn’t change, even though you press Power button on
the set, press Power button on the remote for your confirmation. In case that one of Power
buttons doesn’t function, confirm key signal input (IC903 93 pin) or remote signal input (IC
903 42 pin).
(b) Display of Fluorescent tube
Name of the model (DAV-S300) is displayed on Fluorescent tube when audio
microcomputer switched to Operation Mode.
Next, audio microcomputer (IC903) sets the last function to the Mode and displays it on
fluorescent tube. The last function information is stored in back up memory in audio
microcomputer when the system was turned off.
(c) Start-up of DVD circuit
If DVD Mode was used as you turned off the system, DVDPOW output of audio
microcomputer (IC903 78pin) let the voltage for DVD circuit output from power circuit.
Also, the reset signal of reset IC (IC207) is input into DVD microcomputer(IC202
14pin)that enables DVD microcomputer to start up.
If Tuner Mode was used as you turned off the system, since DVD circuit doesn’t start up,
the function of (e) or later doesn’t work.
(d) Release of Sound Mute
Relay switching output of audio microcomputer (IC903 43 pin) enables to release Mute,
switching speaker relay (RY301, RY331, RY361)
You can hear the mechanical sound of click from speaker relay.
