Macbook A1502 No Power

[WiFiComputers]

I Have Macbook Pro Retina A1502 820-4924, Power LED is there, but it is not turning on, PPBUS_G3H Present, from power rails ppbus_s4_x239 missing not sure if I suppose check at this point, if anyone guide me here
Power supply using .020amp

 

[WiFiComputers]

Liquid damage was near U1900, replaced new chip, I have ppvrtc_g3h 3.3v at pin number 1

 

[JohnB8812]

What voltages are you missing? Exact voltage on PPBUS?

 

[WiFiComputers]

exact voltage at ppbus 12.61v , missing rail ppbus_x239_reg

 

[JohnB8812]

I have no idea what that rail is. Lets start here:

Is PPVRTC_G3H present and a steady 3.3 volts?
Is PP5v_S5 and PP3v3_S5 present?
Is PP5v_S4RS3 present?

 

[WiFiComputers]

Ppvrtc_gr3 is 3.3v steady
pp5v_s5 and pp3v3_s5 present
pp5v_s4rs3 i couldn't find this rail on board, but pp5v_s4 is not present

 

[JohnB8812]

Ok is 5v_S4 straight zero or does it pulse at all? If it's zero, then PM_SLP_S4_L will likely be missing as well. Make sure you're using a known good 60 watt or higher Magsafe 2, but after that, check around the U6100 to see if you have any corroded probe points or resistors. Also check pin 8 of U1950 for corrosion and see if PM_DSW_PWRGD is present. If it is missing, inspect the SMC area for signs of liquid damage.

 

[WiFiComputers]

5V_S4 IS ZERO, U6100 AREA SEEMS OK AND HAS 3V AT PIN 8, ON U1950 NO CORROSION AND DOES HAVE 3.43V. PM_DSW_PWRGD IS PRESENT ASWELL, SMC AREA IS CLEANED

ORIGINALLY HAD LIQUID DAMAGE NEAR U1900, NEAR RESISTANCE r1804 AND U8300

 

[WiFiComputers]

What are the chances board is short to ground somewhere, or chip i installed u1900 is faulty or maybe i didn't solder properly , board is consuming .020amp

 

[JohnB8812]

Possible that your U1900 is bad worth trying another check all traces to it as well

 

[WiFiComputers]

I changed new chip, it's same status

 

[WiFiComputers]

any suggestions #louis

 

[dukefawks]

Is it possible there is crap under the SMC?