LG RHT497H Service Manual page 21

no 2.5v
yeS
is there about 3.3v
at the ic151 Pin1?
yeS
is there about 4v ~ 5v
at the ic151 Pin4?
yeS
check the ic151 and replace
no 1.8v
yeS
is there about 3.3v
at the ic154 pin 3 ?
yeS
check the ic154 and replace
no Sw_5.3va
yeS
is the vcc (5.3v)
Supplied to q158
emiter ?
yeS
is there about 0v
at r179 and r156?
yeS
check the q158 and replace
no
check d154 on i/o and
d127 on SMPS board
no
check the 'Pwr ctl "h"'
signal from µ-coM
no
check power supply 3.3v on i/o board
no
check 5.3va on SMPS board
no
check the "1w_h" signal from µ-coM
3-6