My customer came in with his 11" Air soaked in milk. After drying it would power on with no backlight.
Under the microscope, there was heavy damage and corrosion around U7701. I started with a reflow but the chip was not behaving as expected on the BGA, so I removed it for inspection. Sure enough, both pins on the LCDBKLT_BOOST circuit were blown off.
I replaced the badly damaged U7701 from an 820-3437 donor board. This was the closest donor I had available - was this a mistake? I ran a jumper wire from B1 and B2 to the diode side of L7701 around the other side of the board. Now the board does not power up at all and the magsafe LED remains orange.
I will be home from ERC tomorrow and will be going over this board again - just wondering if my attempted repair could have caused the new problems? The board is heavily damaged from the milk, so it would not be surprising at all if something else crapped out in the meantime.
Under the microscope, there was heavy damage and corrosion around U7701. I started with a reflow but the chip was not behaving as expected on the BGA, so I removed it for inspection. Sure enough, both pins on the LCDBKLT_BOOST circuit were blown off.
I replaced the badly damaged U7701 from an 820-3437 donor board. This was the closest donor I had available - was this a mistake? I ran a jumper wire from B1 and B2 to the diode side of L7701 around the other side of the board. Now the board does not power up at all and the magsafe LED remains orange.
I will be home from ERC tomorrow and will be going over this board again - just wondering if my attempted repair could have caused the new problems? The board is heavily damaged from the milk, so it would not be surprising at all if something else crapped out in the meantime.