Philips CMD305A/05, Service Manual

Date

2012-8-16

NO.

1

NO Power

2

NO audio

output

a

To check whether the volume is at the lowest lever.

c

When the unit is on ZONE mode, change ZONE to ALL ON, then check whether the "no audio output" is caused by the

operation of  ZONE.

I

 To check the voltage of the second pin VDD of Audio processor IC402

PT7313E) , should be 9V, also should check all

the input & output Pins' voltage.

e

To check the voltage of all the pins of preamplifier IC 403

404(4558), the power supply pin should be +12V, and others

pin's voltag is 6V.

f

To check the electric circuit of power amplifier IC501(TDA7388)and audio IC402 (PT7313).

b

To check whether the FFC like CON202 

CON901( 24PIN socket) which were connected the panel and the unit are

inserted in place, whether the lock catch is loose.

c

To check the power supply circuit of IC 202( LM2950) MCU, the input side of the voltage is +12V and the output side is

+5V.

e

To check whether the CF201 crystal oscillate, the oscillation frequence should be 32.768Khz.

d

 ACC+12V is normal for the uint,  and the 6PIN of MCU should have the voltage of +5V6.

Trouble shooting

Trouble shooting

Trouble shooting

Trouble shooting

failure

phenomena

failure cause

remark

Product Model

CED305A

Area

All area

b

To check whether the unit is in MUTE mode , press SOURCE knob and check whether the audio input source is effective.

d

To check whether the 8PIN audio ouput wire on the ISO connector is connected in place,  if the wires are inserted in

wrong place, or short cuirt, it will cause no audio output of the power amplifier( no output or output voltage is low).

a

To check whether the ISO301 16PIN connector is connected well, to check whether the 15A FUSE in the ISO FILTER

BOX is loose.

h

To check the data communication of MCU-CLK

MCU-SDI and MCU-SDO which were between the MCU(The first

second and third Pin) and Servo IC603 BX8804(The 77

78

79 Pin) is normal.

f

The reset knob SW1 was stuck,  the voltage of the two ends of the knob should be +5V when the reset knob is normal.

g

To check the output voltage of the panel, should be  +12V, and the LED should be +9V.

g

.To check the voltage of the 22nd pin of power amplifier IC501(TDA7388),  should be +3V5.

i

To check the voltage of all VDD pins of IC603(BX8804)

IC604(SDRAM) , should be +3V3

h

To check the voltage of the fourth pin ST-BY of IC501 (TDA7388), should be +9V.

j

To check whether the data voltage and data communication of LCD-CE

LCD-CLKE and LCD-DA is normal.

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