LG RH7521W Service Manual page 69

Reset or Power Check.
Check it after connecting the power cable
only for NO Reset or Power ON.
Are the pin 4, 1 of LCN202
+12V, +5V respectively after the power
cable connecting?
YES
Does the pin 3
of LIC303 change 0V to 3.3V
at the power supply initial
input mode?
YES
Are the LX301 oscillating?
YES
<Power>
•Is the pin 5 of LIC505 3.3V?
•Is the pin 4 of LIC505 1.5V?
YES
<Reference>
•1V(IREF):Check pin 112 of LIC301
•1.65V(REFIN):Check pin 134 of LIC301
•2.1V(REFI2):Check pin 12 of LIC201
•2.3V(REF01):Check pin 13 of LIC201
•2.3V(FPDVREF):Check pin 25 of LIC201
•3.3V(REFI):Check pin 38 of LIC201
•1.65V(REF02):Check pin 39 of LIC201
YES
OK
•Check the power(5V,12V)short.
NO
•Check the power cable.
•Repair the power part.
•Check the LIC505(3.3V reg.IC).
NO
•Check the HRST signal of LIC301
NO
•Check the LX301
•Check the oscillation LIC302, LIC303