LG LST-5600A Service Manual page 18

(E) IIC check
YES
IIC SDA and SCL signals are output
from IC211(19 & 18)? Fig.06 & Fig.07
YES
IIC SCL and SDA signals are output
from IC101(W17 & U15)?
Fig.06 IC211(19) :
3.3V IIC SDA signal
Fig.07 IC211(18) :
3.3V IIC SCL signal
NO
NO
3-9
Check IC211
Check IC101