Samsung DV7720KV Service Manual page 34

Troubleshooting
6-10 Focus error check
0V
0.1V
at pin A, D, C, B of
No
Check for pick-up
and connection
between MAIN
and pick-up
Samsung Electronics
No
Check for pulse
SCW1
Yes
Replace pick-up or check for
connector between MAIN
FOCUS ERROR CHEEK
Press PLAY button
Check for signal
at pin 1 of SIC3
Yes
Check for signal
at pin 68 of SIC6
Yes
Check for signal
at pin 63 of SIC6
Yes
Check for voltage
at base of SQ15
: 1.5V
Yes
Check for pulse
at pin 8, 9 of
SIC5
Yes
and pick-up
0.2V
A
0V
B
No
Check for SEMI VR
or PCB pattern
No
Replace parts of EQ circuit
for phase compensation
response of the focus
No
Check for SQ15, SZD1
and power source : -1
No
Replace SIC5
6-10