LENOVO G50-45 NM-A281 ON AND OFF AFTER 10 SECONDS

DC AMP 0.019 ON STANDBY. AFTER PRESSING POWER BUTTON AMP GOES TO 0.250A AND RETURNE 0.019A.

BOARD OFF.

FIRST CHECK RTC CELL. 0.30V ON CELL. REPLACE CELL AND CHECK. BUT SAME PORBLEM.

THEN PREPARE NEW BIOS AND DO BIOS BUT SAME PROBLEM PROBLEM NOT SOLVED.

CHECK 19V CIRCUITE. ITS OK.

CHECK ALWAYS VOLTAGES 3V, 5V, 1.8V, 0.95V ALL ARE OK.

ALL IC'S POWER GOOD OK.

ALL COIL VOLTAGES ARE OK.(WHILE PRESSING POWER BUTTON & STANDBY BOTH).

ABHI KYA KAREEEEE.... THODA TECHNICALY SOCHA AND TRACE DC-DC CIRCUITE.

CHECK ALL DC-DC CIRCUITE. INPUT VOLTAGES ARE OK BUT NO OUTPUT VOLTAGES.

CHECK ALL MOSFET GATE. NOT OK. ALL GATES CONNECTED WITH SAME INPUT.

GATE ARE CONNECTED WITH +VSB. AND +VSB CONVERTER THRUE JUMPER +VSBP.

CHECK THAT JUMPER VOLTAGES. ITS SHOWING 4.80V. WHICH WAS WRONG. IT SHOUTLD BE +19V

SO BACK TRACE & FIND THE BIRTHPLACE OF +VSBP.

+VBSP BIRTHPLACE WAS ON SOT23-3 P-CH MOSFET'S DRAIN. 

MOSFET'S SOURCE 19V B+ OK BUT NO DRAIN VOLTAGE OUT.

CHECK MOSFET IN COLD MODE. GATE & DRAIN SHORT.

FIRST CONFIRM WITH JUMPER THE PR431. 

NOW PRESS POWER BUTTON. DC READING 0.530A & DISPLAY COME.