Chosen Solution
I’ve inherited a not -working MacBook Pro, Retina, early 2015. The previous owner claimed the keyboard didn’t work so the laptop wouldn’t turn on but I’m pretty confident it’s a logic board issue. I’ve tried disconnecting the battery and connecting to power and I get an orange light on the MagSafe connector with no power on. Battery charges as it should. I’ve removed the logic board to check for signs of damage but I’m not overly sure what I’m looking for! I’ve found the attached is the only sign I can see of something out of place. I just wanted to confirm if this would cause the issue of the Mac not powering on and if it’s worth a repair vs replacement?
@wonson absolutely can this be the reason. Looks like your board is a 820-4924 The corrosion between the inductor (L7520)and Mosfet (Q7520) is most likely the cause since both parts are part of your 5V and 3.3V power supply. Clean the board with a soft brush and high-grade 90%+ isopropyl alcohol and see if that works if not then you will have to replace those components.
