Section Three Servicing Cases
3.3.1 Servicing cases
Example 1 Symptom: power not on
Description: insert power plug, standby indicator light is not on and the player cannot be switched
on.
Analysis and troubleshooting: test power board 5V, 3.3V voltage and they are normal; check decode
board 1389 chip power supply and they are 3.3V and 1.8V, which is normal; use oscillograph to check
clock frequency 27MHZ crystal oscillator of 1389 chip and observe whether oscillation frequency is
normal; we find that crystal oscillator has trouble, after changing it, trouble is removed.
Example 2 Symptom: power not on
Description: insert power plug, standby indicator light is not on and the player cannot be switched
on.
Analysis and troubleshooting: test power board 5V, 3.3V voltage and they are normal; check
decode board 27MHZ crystal oscillator frequency and it is normal; test 1389 chip power supply voltage
3.3V, 1.8V and find that there is no 1.8V power supply voltage; check Q306, Q309 and find that Q306
has rosin joint; weld again and trouble is removed.
Example 3 Symptom: no mute function
Description: when playing, press MUTE button, there is mute icon but no mute function.
Analysis and troubleshooting: when playing, test Q213 collector electrode C pin voltage and it is -
2.24V, which is normal; press MUTE button on remote control, use voltage level of multimeter to test
Q213 collector electrode C pin voltage and it is negative voltage, which should be 1.4V in normal
conditions; check 9V power supply voltage and it is normal; test Vd203 anode voltage and it is 0, 7V,
which is normal, so we doubt trouble is caused by Q213; change Q213 and trouble is removed.
Example 4 Symptom: no MIC
Description: when reading disc, sound is normal, there is picture but no microphone function.
Analysis and troubleshooting: power on, use remote control to switch on microphone, insert
microphone, use probe of oscillograph to test OKA pin of MIC board Xs206, speak and there is signal
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