820-3787-A PM_SLP_S3 missing

[KootenayMacGuy]

Hello

This machine was working fine until i disassembled it and replaced the display. There was a fair bit of dust and debris inside and I found corrosion around U5420. I removed the corrosion and reflowed the area and PM_SLP_S3 is still missing (0v). Power adapter is 18.5V @ 20ma. Where do I go from here?

 

[2informaticos]

Be sure to use original 85W Magsafe 2 charger.
This board will not turn on with 45/60W charger; unless battery is connected and holds some charge.

Test the board alone on the desk, without any peripheral connected.
Do you get 3V3_S5/SUS?

 

[KootenayMacGuy]

Thank you.

I connectectd original 85W and board turns on but no image on screen and fans spin full blast.

 

[2informaticos]

Do you get USB activity?
Check if fans run normal when disconnect webcam.

 

[KootenayMacGuy]

Webcam is disconnected. Only Magsafe and LVDS display connector attached, board is out of case on desk. Fans spin up after magsafe connected, then turn off after 8 seconds or so, then turn on again and ramp up to full blast. No image, USB power but no acivity to drive connected.

 

[2informaticos]

Check for knocked off components, or scratched/broken traces.
Test the board without LCD; just check USB activity.