LG RH178H Service Manual page 17

No 5.0VD
YES
NO
Is there about 5.3V
at the IC153 pin 1?
YES
NO
Is there about 4V ~ 5V
at the IC153 pin 4?
YES
Check the IC153
and Replace
No 2.5V
YES
NO
Is there about 3V ~ 3.8V
at the IC151 pin 1?
YES
NO
Is there about 4V ~ 5V
at the IC151 pin 4?
YES
Check the IC151
and Replace
Check 5.3VA on
SMPS Board
Check the 'PWR CTL
H' signal from µ-COM
Check D154 and
D127 on SMPS Board
Check the 'PWR CTL
H' signal from µ-COM
No 3.3V
YES
Is there about 3.8V at
the IC152 pin1?
YES
Is there about 4V~ 5V
at the IC152 pin4?
YES
Check the IC152
and Replace
No SW_5.3VA
YES
Is the VCC (5.3V) sup-
plied to Q158 Emitor?
YES
Is there about 0V
at R179 and R156?
YES
Check Q158 and
Replace
3-5
NO
Check or Replace
the D127
NO
Check the 'PWR CTL
"H"'signal from µ-com
NO
Check 5.3VA on
SMPS Board
NO
Check the 'STANBY
H'signal from µ-COM