Philips CEM2000/00 Service Manual page 23

Product Model CEM2000
failure
NO.
phenomena
a. To check whether it is connect well of the ISO connector (4 PIN power input ). Whether it is loose of the 15A fuse of the
ISO connector, or insert non in place.
b. To check whether there is any contamination and bad contact on the 22 Pin male/female connector on the panel and main
board.
c. To check the power supply of main board B+ ACC should be +12V; The voltage of stabilivolt of ACC power supply circuit
ZD3 (6V8) should be 6V8.
1
NO Power d.To check the voltage of the 17 pin of U1 MCU should be +4V8.
e. To check the voltage of the 15 pin 16 pin 47 pin of U1 MCU should be +5V; The output voltage of U4 (LM2950) should
be +5V.
f. To check the oscillation frequence of crystal XT4 shuold be 7.2MHz .
g.To check the resistor network of NR1 (4K7).
H. To check the voltage of the15 pin(Lamp Vcc) of CN5 should be 6V4.
a. To check whether the volume knob is turn to the minimum position.
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 8 PIN audio output wire of ISO connector is correct; wrong connection or short circuit
NO audio to the ground will caused the protection of the power amplifier( no voltage output).
2
output
d . To check the circuit of power amplifier U3 (LV47002) and VOLUME U5(7313 IC).
e. To check the normal voltage of 22 PIN(MUTE) of power amplifier U3(LV47002) , normally should be 4V1
f. To check the voltage of 2 pin of audio processor U5 7313 IC , should be +9V0.
g. To check the voltage of control PIN SDA SCL the 27 28 pin of audio processor U5 7313 IC , should be +4V9.
a. To check the antenna of the tuner.
b. To check whether the strength of then input signal of the tuner is too weak.
c. To check the voltage of the 7 pin 22 pin 33 pin 40 pin 41 pin 43 pin of the U2 of the tuner IC 7703 , should be
+5V0.
3
d. To check the voltage of the 26 pin(SDA) of the tuner IC(7703), should be +3V8; the 27 pin(SCL) should be +4V2.
e. To check the L output voltage of the 37 pin of tuner IC(7703) should be 1V7, the 38 pin R output voltage , should be 1V7.
Tate
failure cause
2011-11-19
remark
24