Sony DVP-FX740DT Service Manual ▷ View online
7-2E
DVP-FX740DT
Method 2. (When the adjustment mode is not dislayed)
1) After exchanging parts, it turns on power with the LCD board
1) After exchanging parts, it turns on power with the LCD board
seen.
2) The DC voltage of measurement point (VCOMDC) in the LCD
board is measured with a digital voltmeter.
3) Adjust to become 1.59±0.03V with the VOL [+] or [–] button.
4) The adjustment mode is ended pushing the [ENTER] button of
4) The adjustment mode is ended pushing the [ENTER] button of
standard commander (Or, this set).
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LCD board
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Measurement point (VCOMDC)
8-1
DVP-FX740DT
SECTION 8
TROUBLESHOOTING
8-1. ELECTRICAL TROUBLE SHOOTING GUIDE
No power on
by adaptor
No power on
by battery
Is adaptor
out 9.5V?
YES
NO
Is P1 OK?
Replace P1
Is D2 OK?
NO +3.3V
NO P_3V3
NO +1.8V
Is U3 OK?
Replace U3
Is Q12 OK?
Is U3 OK?
Replace Q12
NO LCD
power
Replace U3
Is U4 OK?
Replace U4
Replace D2
Replace adaptor
Is battery OK?
Replace Q5
Is Q5 OK?
Replace battery
AUDIO OUT ABNORMAL
SPEAKER ABNORMAL
Is J9, J10 or TCN4,
TCN5 OK?
Replace J9, J10 or
TCN4, TCN5
Replace U13
Replace U7 (MT1389LP)
Replace speaker
Is U13 OK?
Is speaker OK?
Check audio jack & mode
Check U14
Check signals from
U7 (MT1389LP)
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
1. A. Power (DC-DC Converter) circuit
B. Audio out abnormal
C. Speaker abnormal
Is U3 OK?
NO +5V
Replace U3
NO
YES
Replace U2
NO
Replace U15
NO
Is USB_VCC
OK?
YES
Is AVCC
OK?
YES
Is U5 OK?
Replace U5
NO
YES
8-2
DVP-FX740DT
VIDEO OUT ABNORMAL
OPEN/CLOSE ABNORMAL
NO CHARGING
Is 9.5V OK?
Check P1
Is Q12, U5 OK?
Replace Q12, U5
Is U3 OK?
Replace U3
Is Q55 OK?
Replace Q55
Check SW3 & SW4
Check the connection of part
Check traverse
PICTURE ABNORMAL
DISC ERROR
Check video jack mode
Check the disc
Check disc
Check the traverse
Check traverse
Check the SDRAM
Refer to servo part
Refer to servo part
Check LC filter
Check video signals from
U7 (MT1389LP)
YES
YES
YES
D. Video out abnormal
G. Open/close abnormal
H. Charging circuit
E. Picture abnormal
F. Disc error
NO
NO
NO
NO
Refer to servo part
Is Q4 OK?
Replace Q4
YES
NO
Is J2 OK?
Replace J2
YES
NO
8-3
DVP-FX740DT
Power is on
Does logo appear
on the screen?
Check power & clock
Does
the moving picture
of the DVD disc play
on the screen
normally?
Does
the moving picture
of the CD disc play
on the screen
normally?
Is MPEG data
signal normal?
Is error signal
normal?
Check CD/DVD
DSP output signal
Check MPEG decoder
input signal
Is clock normal?
Check clock signal
Check clock signal
Does the audio
signal output from MPEG
decoder?
Does the
audio sound output
normally?
2. MPEG Circuit
NO
NO
NO
YES
YES
YES
YES
YES
OK
OK
U7 (MT1389LP)
U7 (MT1389LP)
OK
YES
NO
YES
NO
NO
NO
YES
NO
NO
Check CD/DVD
DSP output signal
Check MPEG decoder
input signal
Check CD/DVD
DSP output signal
Check MPEG decoder
input signal
Is MPEG data
signal normal?
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