Analysis and troubleshooting: this trouble often appears in video decode part; after power off for a
period, picture output is normal; after playing for a period (about 5 minutes), picture has interference; to
analyse this trouble, play DVD disc normally firstly, use iron to heat chip 1389; after heating, picture has
interference; after changing chip 1389, it is OK.
[ Example
] Symptom: no sound output
[ Example
] Symptom: the player not power on
14
Description: no sound output when playing any discs; SCART and HDMI also have no sound output;
no shock sound when power on and off.
Analysis and troubleshooting: when playing discs, use oscillograph to test signals on TC224,
TC223, TC222, TC221, TC240, TC241 capacitor and there is sound output; now check B electrode of
Q205 and it is 0.7V, then test C electrode voltage of Q218 and it is 1.65V; test E electrode voltage of
Q218 and it is 8. 3V; then test B electrode voltage of Q212 and it is 3.4V, and we find that triode is still in
cutoff state; when using multimeter to test, CE electrode of triode has open circuit; after changing it,
trouble is removed.
15
Description: when inserting power plug, power indicator light is always on; but when pressing ON
button, the player cannot power on and work.
Analysis and troubleshooting: this player is false standby, so if power indicator light is on, it means
that power working is normal and trouble should lie in decode part; test power circuit, reset circuit and
2
clock circuit and they are all normal; when testing I C bus SDA, SCL, we fin that SDA keeps low level
2
(about 1.3V) all the time; check I C bus line and there is no other element disturbance, so trouble should
lie in IC part; change U202 location IC 24C02, trouble is removed.
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