HP 15AB- QUANTA X12A MAINBOARD NO POWER ON 

BOARD  POWER ON OFF, CYCLE APPROX 4.SECONDS

AFTER On VCORE FOR 550mS

3V AND  5V CONT.. ON

VGA CORE 0.90V AND 1.35V VRAM   FOR 750mS

1.05V for 700MS, 1.35V RAM for 700MS

EC PIN21. PMPWRBTN# for 4.8SECONDS

PIN19,PIN87 PIN81 PIN97 continuous HIGH

PIN20. EC_PWROK Pin83 FOR 500mS 

PIN33,PIN35,PIN98 FOR 700mS

PIN88. FOR 900ms SUSB#

PIN3,PIN34,PIN80 PIN100 continuous 3.3V

Open PMPWRBTN# PIN FROM EC PAD NOW  HIGH CONT..HIGH AFTER PWR BTN PRESS ALSO

SO REFLOW CPU

ALL OK

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ANOTHER CASE NO POWER BUT  THISD TIME B+ CYCLE

No power, NO PROPER B+ or ACLED LIT, B+ Trip WF BELOW

ACDET 2.6V OK,REGN 6V BUT NO ACOK

INJECT 3V TO B+ LINE NO LEAKAGE ON ANY OUTPUT COILS

JUST FOR TESTING WHEN ACFET D -S SHORT WITH TWEEZER, B+ OK, ACLED WHITE LIT

SO REPLACE ACFET OK

NOW ADP PLUG. 0.007A,ACLED LIT

ALL GOOD