LG LAC-M2500R Service Manual page 8

(3) INITIAL READING IS NOT CARRIED OUT.
Slide motor moves
(With disc)
YES
NO
Spindle motor turns
WAVEFORM #1
YES (with disc)
Does RF waveform appear?
IC502 Pin8
WAVEFORM #2
YES
Check the Voltage change of
NO
CN503 Pin10(6.4~6.8V)
YES
Check the Voltage IC501 Pin31
(1.4V~1.8V)
YES
Check the Data transmission from
CN503(18,20,21) to CD DSP
WAVEFORM #5
YES
NO
Check the Data transmission from
CN503 Pin19 to MICOM
WAVEFORM #5
YES
Check the TRVP
Voltage
IC501 Pin31
YES
Check the change of SL
+, SL - Voltage
IC504 Pin13,14
Laser light check ?
A
Does FA+ waveform appear at
IC501 Pin31?
WAVEFORM #3
focus coil drive wareform.
YES
Does TE waveform appear at
IC502 Pin21?
WAVEFORM #4
TRACKING ERROR wareform
YES
Is rotation normal?
YES
Is there no dropout of RF signal?
- 2-3 -
Defective connector
NO
CN503
NO
Defective IC501
Defective connector
NO
CN503
Defective MICOM
Defective connector
CN503
NO
Defective IC504
1.4~1.8V
NO
Defective IC501
3~4V
NO
Defective IC504
YES
Defective contact CN502
Defective PICK-UP
NO
NO
NO
Defective IC501
Defective PICK-UP
YES