Philips CMB1100/55, Service Manual

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21
NO.
2011-11-15 Date Product Model
$OO$UHD
Area
failure cause failure remark
NO Power
f. To check the oscillation frequence of crystal X201 , shuold be 8MHz, and for the crystal X202 should
be 32.768KHZ.
a. To check whether it is connect well of the ISO connector (4PIN power input ). Whether it is loose of
the 15A fuse of the ISO connector, or insert non in place.
b. To check whether the reset button Sw201 is long term functional then caused short circuit and no
power.
1
d. To check the power supply of main board B+
ǃ
ACC should be +12V; The voltage of stabilivolt of
ACC power supply circuit ZD210 (6V8) should be 6V8.
e. To check the voltage of the 19 pin (AVDD) of MCU (T5CL8) should be +3V3; The output voltage of
IC307 (LM2950) should be +3V3.
c. To check whether there is any contamination and bad contact on the 22 Pin male/female connector
on the panel and main board.
g. To check Panel LED +5V voltage , should be normal.
2 NO audio
output
f. To check the voltage of control PIN SDA
ǃ
SCL
˄
the 27
ǃ
28pin
˅
of audio processor IC402
˄ PT7313E ˅ , should be +3V3.
e. To check the normal voltage of 22 PIN(MUTE) of power amplifier IC501(LV47004) , normally should
be 4V.
d . To check the circuit of power amplifier IC501 (LV47004) and VOL IC403 (PT7313E).
b. To check whether the unit is at MUTE mode, press SOURCE button and check whether it is effective
of the input sound source.
c. To check whether the connection of 8PIN audio output wire of ISO connector is correct; wrong
connection or short circuit to the ground will caused the protection of the power amplifier( no voltage
output).
a. To check whether the volume knob is turn to the minimum position.
a. To check the antenna of the tuner.
b. To check whether the strength of then input signal of the tuner is too weak.
3
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f. To check the L output voltage of the 5 pin of tuner should be 1V5, the 6 pin R output voltage , should
be 1V5.
d. To check the voltage of the 10 pin(RES) of the tuner, should be +3V6; the 11 pin(CLK) should be
+3V1; the 12 pin(date) should be +2V8.
e. To check the oscillation frequence of crystal XT001 of the tuner, should be 32.768KHZ.
c. To check the voltage of the 7 pin(VDD) of the tuner , should be +3V3.
Trouble shooting
CMB1100