Desktop Power Sequence

DESKTOP POWER ON SEQUNCE PSIN(PANSW)= ON OFF SWITCH PSOUT(PWRON)= SIO TO ICH(PCH) SLP3(SUSB)= ICH(PCH) TO SIO SLP4(SUSC) = ICH (PCH) TO SIO PSON = SIO TO SMPS

PSON

3

7

RSMRST

5   PSOUT(PWRON) SLP_S3

SIO

6

SLP_S4

ICH or PCH

3VSB

2

1 VSB

4

     )     W     S     N     A     P      (     N     I     S     P

1: check VSB voltage at SIO if voltage not coming check power supply or relevant circuit 2: check RSMRST 3volt signal at SIO if signal absent replace SIO 3: check power switch PSIN & PSOUT signal variation from 3 volt or zero volt if there is no variation means SIO bad. 4:check SLP3 (SUSB) AND SLP4(SUSC) signal from zero volt to 3volt if no variation means ICH(PCH) BAD