LG RC-185 Service Manual page 60

VDR ELECTRICAL TROUBLESHOOTING GUIDE
No 3.3V
NO
Is the Vcc(3.8V) sup-
plied to IC153 pin 1?
YES
NO
Is the IC153 pin4 '
H'?
YES
Check or Replace
the IC153
No 12VL
NO
Is the Vcc(13.5V) sup-
plied to IC155 pin 1?
YES
NO
Is the IC155 pin4
'H'?
YES
Check or Replace
the IC155
Check or Replace
the D127
Check the DVD CTL
"H" signal from µ-com
Check or Replace
the D124
Check the DVD CTL
"H" signal from µ-com
3-68
No 2.5V
NO NO
Is the Vcc(13.5V) sup-
plied to D156 anode?
YES YES
NO
Is the IC154 pin4
'H'?
YES
Check or Replace
the IC154
No 5VL
NO
Is the Vcc(5.5V) sup-
plied to IC156 pin 1?
YES
NO
Is the IC156 pin4
'H'?
YES
Check or Replace
the IC156
Check or Replace
the D156
Check the DVD CTL
"H" signal from µ-com
Check or Replace
the D128
Check the DVD CTL
"H" signal from µ-com