Samsung DV7700, DV4720 Troubleshooting

Samsung Electronics

6-1

6. Troubleshooting

Check if PF1 is OK

Check if Power Trans

output is OK

Check for voltage

“8V”

Check for voltage

“-8V”

Check for voltage

“5V”

Check for voltage

“-5V”

Check for voltage Ever “5V”

Replace PF1

Replace PFT1,PIC1,PIC2,

PR4,PR75,PD1

Replace power PCB ASS’Y

Replace Power Trans

Replace PIC4

Replace PIC5

Replace PQ5,PQ6

Replace PQ3,PQ4

Replace PFET1,PIC1,PIC2,PR4,PR75,PD1

6-1 Power source problem

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

NO

NO

Samsung Electronics

6-2

6-2 Blue background not shown (LD,CD)

Check for 4fsc signal

at TP1

Check for Video signal

at pin 78 of VIC2

Check for video signal

at NC6

Check for video signal

at pin 7of NIC4

Check for video signal

at emitter of NQ1,NQ2

Check for micom

interface

Check for video signal

at base of VQ28

Replace VX1

Replace MIC101

Adjust VCTC1

Check for video signal at
base of VQ25, VQ19
,VQ20,VQ21

Replace VQ28

Replace NIC4

Check TV mode:NTSC or PAL

Check for connection of VCW1 on the FMV PCB

Replace NQ1,NQ2

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

YES

NO

Troubleshooting

Check for video signal

at pin7 of VIC10 on the

FMV PCB

Check for connection of VCW1

on the FMV PCB

NO

Samsung Electronics

6-3

6-3 No disc error

More than 0.4V (2V generally)

0V

More than

0.3V
0V

Yes

No

Yes

Yes

Yes

Yes

No

No

Yes

No

No

No

NO DISC ERROR

Check for
signal at Pin 98 of SIC6
(during playing) : more

than 0.4V

Check for

signal at Pin 100 of SIC6

(during playing) : more

than 0.3V

Check for

voltage Pin 53 of SIC6

: from 5V to 0V

Replace MIC 1

Check if

pick-up goes up and

down when PLAY button

is pressed

Check if
pick-up emits
LASER beam

Replace SIC 6

See FOCUS

does not play

Check for

voltage at Pin 6

of SCW 1 : -5V

Check for change of voltage

at Pin 8 of SCW 1

when PLAY button is

pressed : 1.2V

2V

Replace pick-up

Replace SQI

5V

0V

100
4DSUM

53
FL

Troubleshooting

Samsung Electronics

6-4

6-4 No Video Signal

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

See "Blue - background not shown"

check for video

signal at PIN 70

of VIC 1

check for video

signal at emitter

of VQ1

check for DIGITAL

signal at PIN 48 THRUY

PIN 55 of VIC 2

check for V-sync signal

at PIN 39 of VIC 1

Replace VIC 1

Replace VQ1

Replace VIC3

check for IRQ signal

at PIN 90 of VIC 2

Replace VIC 2

check for HREF,PBHD

signal at

PIN 41,43 of VIC 2

See "LD DOES NOT PLAY"

Troubleshooting

Samsung Electronics

6-5

6-5 LD does not play

Yes

No

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

Yes

Yes

No

No

LD DOES NOT PLAY

Check for signal

at Pin 35 of

SIC6

Check for voltage

at Pin 31 of SIC6

: 2.5V

Check for signal

at Pin 23 of SIC6

: 2 ~ 3V

Check for signal

at Pin 27 of SIC6

: 1 ~ 2V

Check for signal

at Pin 32 of SIC6

: 2 ~ 3V

Check for signal

at Pin 46 of SIC6

DISC is

defective

Replace SIC6

Replace TIC2

Replace SIC6

Replace SIC6

Replace SIC6

Check for

frequency at Pin 45 of

SIC6 : 15.7KHz

Check for

frequency at Pin 42 of

SIC6 : 14.3MHz

Replace SIC6

Replace SIC6

Replace VIC2

5V

0V

15.7KHz

about 3V

2.5V

63.5µsec

5V

0V

63.5µsec

Troubleshooting

Samsung Electronics

6-6

6-6 CD does not play

No

Yes

No

Yes

No

Yes

No

CD DOES NOT PLAY

Check for DIGITAL

sound of LD

Check if spindle

motor is O.K.

See "No Digital

Sound"

Check for change of

voltage at Pin 34 of SIC 6

when PLAY button is pressed

: 2V 3V

Check for voltage at

Pin 47, 46 of SIC 6

: 5V, 0V

See "SPINDLE MOTOR dose not work"

Replace

SIC 6

Troubleshooting