LG HT552TH Service Manual page 40

3) Tray open waveform
4. SLED CONTROL RELATED SIGNAL (NO DISC CONDITION)
FIG 3-3
FIG 4-1
3-13
OPENSW(P4402 PIN3)
CLOSESW(P4402 PIN4)
OPEN(IC401 PIN 1)
CLOSE(IC401 PIN 2)
SLO(2.0V/1.4V/1.0V)
(IC501 PIN 209)
DRV_MUTE(5V) – (IC401 PIN 21)
SLED+(4.7V/3.6V/1.9V)
(IC401 PIN 17)
SLED-(5.3V/3.7V/2.5V)
(IC401 PIN 18)