[ Example
Symptom: no MIC
4 ]
Description: when reading disc, sound is normal, there is picture but no microphone function.
Analysis and troubleshooting: power on, use remote controller to switch on MIC, insert microphone,
use oscillograph probe to test OKA pin of MIC board Xs601, speak toward it and there is signal output;
check decode board U210 OKR, OKL and there is signal input; test U210 power supply and it is 3.3V,
which is normal; use oscillograph to test the 3 data clock of SACLK, SBCLS, SLRCK outputted by 1389
chip to U210 and they are normal, so we doubt that maybe U210 has trouble or rosin joint; weld U210
again and test and it is OK, so trouble is removed.
[ Example
Symptom: no sound
[ Example 6 ]Symptom: decode board burnt down
[ Example 7 ]Symptom: not read disc
[ Example 8 ]Symptom: centre and subwoofer have no wave
5 ]
Description: there is picture but no sound output
Analysis and troubleshooting: check U207 power supply voltage DV3.3V, VCC5V and they are
normal; use oscillograph to test 3 audio data outputted by 1389 chip to U207 and they are normal; then
test 3 clock signals of SBCLK, SLRCK, SACLK and there is data clock input; check reset signal RESET#
and there is 3.3V reset voltage, which is normal; use remote controller to select reset in setup menu and
trouble still exists, so we doubt that it is U207 that has rosin joint or trouble; weld again and trouble still
exists; change U207 Cs4360, trouble is removed.
Description: circuit around nerve line jack on decode board is burnt down
Analysis and troubleshooting: we preliminarily judge the trouble is cause by short circuit to ground
of loader power supply voltage; check pin 24 power supply pin of nerve line jack and it is short-circuited
to ground; remove loader and then check power supply pin of pin 24 of nerve line and it is normal, so we
doubt that the loader is short-circuited to ground; change loader and trouble is removed.
Description: do not read any disc
Analysis and troubleshooting: load disc and test and find that laser head has action of focus but no
light emission, so we judge preliminarily that loader laser head is burnt down or 1389 has trouble,
change loader and trouble still exists; check LD02, LD02 of 1389 and there is no output; change 1389
and trouble is removed.
Description: centre and subwoofer have no waveform output
Analysis and troubleshooting: load 5.1CH test disc and test each waveform and find that pin 1, 7 of
4558IC with location number U211 have no waveform output; change 4558IC and trouble is removed.
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