820-3115 - Short on PPBUS_G3HOT?

Hi everyone!

I’m a first time poster, and long time user of iFixit products. I’ve recently delved into the world of microsoldering , schematics and advanced troubleshooting.

After watching loads of Jessa and Louis’ videos I feel that I’ve got a rudimentary understanding of how Apple products work at component level.

I purchased a faulty A1278 (820-3115) with obvious signs of water damage and previous repair attempt. I replaced U7000 because I wasn’t getting a green light on MagSafe. Now the new U7000 is in, I have all of the relevant voltages present for the OneWire circuit to function, but I only get a green light for 5 seconds, which disappears and then reappears.

All pins on U7000 have a resistance in diode mode other than 27 and 28, which appear to be short; along with C7030 and C7031.

Q7085 is getting around 16V on source and 15V on gate, but not opening.

I hope I’ve provided enough information for one of you lovely lot to help me out here. Any ideas would me much appreciated because I’m at a loss now.

Thanks in advance, and please let me know if I’ve missed anything obvious!

Joe.