LG DP132 Service Manual page 17

When you plug power cord and turn the unit on, LED light won't turn red, the unit won't
read disc nornally.
1-3. Please check main board IC U2 singal and its peripheral circuit.
1) Please check if output voltage 3.3 V from IC U2 pin1, 3, 9, 14, 27, 43, 49 is normal.
If output voltage 3.3 V is not normal, please check 3.3 V power circuit of main board.
2) Please check every singal connected between IC U2 and IC U1, especially including DATA and
ADDRESS signal.
If DATA and ADDRESS signal is not normally output, please check if U2 is in failure.
ONE POINT REPAIR GUIDE
< Main Board Top View >
U1
3-4
U2