Samsung DV7700, DV4720 Troubleshooting

6. Troubleshooting

6-1 Power source problem

							NO
Check if PF1 is OK									Replace PF1
		YES							YES
										YES
				NO
Check if Power Trans								Replace Power Trans
output is OK
		YES
						NO
Check for voltage									Replace PIC4
“8V”
		YES
					NO
Check for voltage									Replace PIC5
“-8V”

YES

NO

NO

Replace PFT1,PIC1,PIC2,

PR4,PR75,PD1

NO

Replace power PCB ASS’Y

Check for voltage					Replace PQ5,PQ6
“5V”
	YES
			NO
Check for voltage					Replace PQ3,PQ4
“-5V”
	YES
			NO
Check for voltage Ever “5V”					Replace PFET1,PIC1,PIC2,PR4,PR75,PD1

6-1	Samsung Electronics

Troubleshooting

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

NO

NO

Adjust VCTC1

Replace VX1

Check for 4fsc signal

at TP1

YES

NO

NO

Check for Video signal

Check for micom

Replace MIC101

at pin 78 of VIC2

interface

YES

YES

	NO								NO
Check for video signal						Check for video signal
at NC6							at base of VQ28
	YES							YES
							Replace VQ28
		NO
Check for video signal							Replace NIC4
at pin 7of NIC4						Check TV mode:NTSC or PAL

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

	YES
		NO
Check for video signal
					Check for connection of VCW1
at pin7 of VIC10 on the
					on the FMV PCB
FMV PCB

YES

NO

Check for video signal

at emitter of NQ1,NQ2 Check for connection of VCW1 on the FMV PCB Replace NQ1,NQ2

Samsung Electronics

6-2

Troubleshooting

6-3 No disc error

NO DISC ERROR

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

than 0.4V

Yes

More than 0.3V

0V

Check for

signal at Pin 100 of SIC6 (during playing) : more than 0.3V

Yes

Check for voltage Pin 53 of SIC6

: from 5V to 0V

100

4DSUM

53		5V		Yes
			0V
FL

More than 0.4V (2V generally)

0V

No

Check if pick-up goes up and

down when PLAY button is pressed

No

Yes

Check if pick-up emits LASER beam

No Yes

Replace SIC 6

No

See FOCUS does not play

No

Check for voltage at Pin 6

of SCW 1 : -5V No Check for change of voltage

at Pin 8 of SCW 1 when PLAY button is pressed : 1.2V

2V

Replace SQI

Yes

Replace MIC 1

Replace pick-up

6-3	Samsung Electronics

Troubleshooting

6-4 No Video Signal

check for video signal at PIN 70 of VIC 1

Yes

check for DIGITAL signal at PIN 48 THRUY PIN 55 of VIC 2

Yes

check for V-sync signal at PIN 39 of VIC 1

Yes

check for IRQ signal at PIN 90 of VIC 2

Yes

check for HREF,PBHD signal at

PIN 41,43 of VIC 2

No	check for video	No
	signal at emitter		Replace VQ1
	of VQ1

Replace VIC3

No

No

Replace VIC 1

No

Replace VIC 2

No

See "LD DOES NOT PLAY"

Yes

See "Blue - background not shown"

Samsung Electronics

6-4

Troubleshooting

6-5 LD does not play

LD DOES NOT PLAY

63.5µsec

about 3V

2.5V

No

Replace SIC6

Check for signal at Pin 35 of SIC6

Yes

Check for voltage at Pin 31 of SIC6 : 2.5V

					Yes
		No		Check for signal
Replace TIC2
				at Pin 23 of SIC6
				: 2 ~ 3V
		No			Yes
				Check for signal
Replace SIC6
				at Pin 27 of SIC6
				: 1 ~ 2V
					Yes
		No		Check for signal
Replace SIC6
				at Pin 32 of SIC6
				: 2 ~ 3V
		No			Yes
				Check for signal
Replace SIC6
				at Pin 46 of SIC6
					Yes
				DISC is
				defective

15.7KHz

No

5V

0V

Yes

Check for

frequency at Pin 45 of

Replace SIC6

SIC6 : 15.7KHz

No

No

Check for

frequency at Pin 42 of

Replace VIC2

SIC6 : 14.3MHz

Yes

Replace SIC6

5V

0V

63.5µsec

6-5	Samsung Electronics

Troubleshooting

6-6 CD does not play

CD DOES NOT PLAY

Check for DIGITAL	No		See "No Digital
sound of LD			Sound"

Yes

No

Check if spindle motor is O.K.

Yes

Check for change of			No
voltage at Pin 34 of SIC 6
					Replace
when PLAY button is pressed
: 2V		3V			SIC 6

Yes

Check for voltage at	No
Pin 47, 46 of SIC 6
: 5V, 0V

See "SPINDLE MOTOR dose not work"

Samsung Electronics

6-6