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Typical maintenance samples
Example1
[Symptom]: After the player is powered on, DVD or VCR indicator will keep lighting. The
buttons don’t response.
[Analyze]: Power supply is normal, but the system program doesn’t work normally, and so
does the CPU (IC601). No signal is output at testing switch (P606) on
running mechanism
, and
no lifting voltage is output. The power PCB supplies normally. So the circuit between testing
switch on reel gear total Ass’y and power PCB is open. D601 is defective solder.
Example2
[Symptom]: The player doesn’t response after it is powered on.
[Analyze]: The symptom may be caused by the following reasons: power supply is not
normal, operating clock doesn’t work normally or CPU doesn’t reset. Test the IC602 with
OSC and find that the reset voltage on it is sufficient, instead supply voltage and clock signal
are in normal condition. So replace IC602.
Example3
[Symptom]: The buttons on the front panel don’t repose. Instead the remote control works
normally and the LED displays normally.
[Analyze]: Power supply from CPU, N701 is normal. Data communication circuit between
front panel and CPU has failure. Check connections on PCB. LED.S.IN signal amplitude is
insufficient. So lift resistance R608 has failure. Replace the resistance.
Example4
[Symptom]: In VCR mode, the playback picture is rolling up and down, and then the picture
disappears.
[Analyze]: The performance of the component on the main PCB declines because of the high
temperature. Test the voltage and main clock signal with OSC, the amplitude of clock signal at
pin38 of CPU decreases 500mV. Check the clock signal output at IC401, the IC works
normally. So signal transmission wire has failure. The amplitude of J139 (inductance 12uH)
on the transmission wire decreases. Replace the inductance.
Example5
[Symptom]: The characters on OSD have distortion.
[Analyze]: The module controlled by CPU doesn’t work normally. Test the supply output at
OSD with OSC, it works normally. LECHA signal and the wave are normal; HLF voltage is
normal with a few inferences on wave. Replace the ground filter capacitor CS10.
Example6
[Symptom]: Audio noises can be heard with power on/off.
[Analyze]: Test the on/ff mute diode Q201, Q202, no controlling signal output during
powering on/off. Test the signal wire of CPU, controlling signal is output normally while
powering on/off. J234 on transmission is open. Replace it.
Example7
Symptom: The player can operate normally, but N701 displays incompletely.
[Analyze] Pins on N701is defective solder or chip doesn’t output. Test the pins on the chip
with OSC, then test pins on display of N701 with OSC, no output is detected at pins. Pins on
N701 are defective solder.
Example8
Summary of Contents for DVCR101
Page 1: ...DVCR101 DVD VCR PLAYER SERVICE MANUAL...
Page 41: ...40 2 TOP COVER REMOVAL...
Page 42: ...41 3 LOGIC PCB DISASSEMBLY...
Page 43: ...42 4 DECK AND MAIN PARTS DISASSEMBLY...
Page 44: ...43 5 MAIN PCB DISASSEMBLY...
Page 45: ...44 6 MAIN CHASSIS DISASSEMBLY...
Page 46: ...45 7 EXPLODE VIEW CIRCUIT DIAGRAM...
Page 47: ...46...
Page 48: ...47...
Page 49: ...48...
Page 50: ...49...
Page 51: ...50...
