Help with fault finding after water damage.
Phone was in a sports bag with a water bottle that leaked. I dissembled the phone (just like the teardown posted on this site Galaxy S3 Teardown).
Left it in an airtight bag with some silica gel for 48 hours.
Cleaned all parts throughly in IPA bath, dried and inspected all connectors, tracks, components etc under microscope, with no visible damage.
Reassembled and everything working perfectly … until I inserted the wall charger. Then the screen immediately went black (including soft keys) and has not worked since.
The phone itself works fine except for the display. I have connected to it with ADB, backed it all up and verified that the touchscreen and soft keys are working fine. I have tested the screen assembly in a different phone and it works fine, so the screen/lcd/digi
Due to the initial cause (water damage) and the way in which it failed (during connection of external power), I suspect the problem is power supply related, i.e. the mainboard is not supplying power to the lcd or something similar.
Has anybody seen a similar set of symptoms? Or can anyone tell me which (if either) of the two main power ICs on the main board control the LCD? Or does anyone have a link to a schematic for the board?
I suspect this could be an easy repair if I can find the fault, and may save people the cost and hassle of replacing an entire mainboard if I can provide a "HowTo".
Kevin Buckle, I added the service manual for the phone to the device page. Scroll all the way down until you find the Service Information paragraph and click on the blue link. This will download the manual with the schematic etc. Amazingly enough the troubleshooting guides first step "Power-on the phone and check the power-on sound or motor biration. Sound or Biration is ok? No--> Change the MEA FRONT-OCTA LCD ASSY So you may be on to something here.
Hope this helps, good luck.