Waveforms Of Major Check Point - LG FFH-185A Service Manual

WAVEFORMS OF MAJOR CHECK POINT

1. HF signal (RF signal ) waveform
(Test Point) during normal play
3. Focus coil drive waveform(Pin NO 1, 2 of IC 502)
• When focus search failed or there is no disc on the tray
4. Tracking coil drive waveform (pin NO
and TEO during track traverse
(1) When time division is 20nS/div
CH1 : TEO(Test Point)
(
1V/Div.
CH2 : TRACK COIL DRIVE
SIGNAL 2V/Div.
(3) When time division is 0.5nS/div.
(During backward Track Traverse)
(
CH1 : TEO(Test Point)
1V/Div.
CH2 : TRACKING COIL DRIVE
SIGNAL 2V/Div.
2. EFM signal (pin
0.5V/Div.
(
500nS/Div.
OV
• Focus coil drive waveform(pin NO 1, 2 of IC 502) and
OV
, of IC 502)
26 27
(2) When time division 0.5nS/div.
OV
(CH1)
OV
(CH2)
5. Feed motor drive waveform(pin NO 11, 12 of IC 502)
OV
OV
(CH2)
- 2-8 -
IC 501)waveform
33
during Normal Play
FOK (pin NO of IC 501) when focus search is
40
accomplished
(
CH1 : FOCUS COIL DRIVE
SIGNAL 2V/Div.
CH2 : FOAK
(During forward track traverse)
(
CH1 : TEO(Test Point)
1V/Div.
CH2 : TRACKING COIL DRIVE
SIGNAL 2V/Div.
During normal play
2V/Div.
(
500nS/Div.
OV
OV
(CH1)
OV
(CH2)
OV
(CH1)
OV
(CH2)
0.5V/Div.
(
500nS/Div.
OV