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LENOVO G550S LA-9901P NO VCORE PROBLEM (SOLVED)

T

Test Admin (18 Mar 2025)

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PSU  SHOWING 0.24AMP

3.3V AND 5V ALW PRESENT

 

OTHER VOLTAGES MEASURED:

1.04V    PL701

0.88V.  PL601

1.5V.      PL501

2.62V    PL302

 1.5V      VDDQ

 

DURING VOLTAGE TEST FOUND PU901 (NCP6132A) PIN4 VRON 3V PRESENT BUT PIN1 VCC 3.6V ONLY INSTEED OF 5V

BECAUSE U38  5VALW TO 5VS SWITCH SOURCE TRANSFER  3.6V ONLY, 

SVID CLOCK PULSE SEEN  AS SHOWN BELOW WF

SVID SCLK WF ZOOMED IMAGE

U38 GATE 15.2V ok but OUTPUT  not Transferred properly

SO Replaced U38 N-CH MOSFET

 

all ok, booting tested by USB init.

FOR MORE SIMPLE BUT ILLUSTRATIVE CASE STUDY,STAY LOGIN TO YOUR OWN WEBSITE.... www.EasyMB.in

 

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