5 
3 Any other reason why this MacBook will not Charge or Power?
MacBook Pro A1278 820-2327
I have here a Macbook Unibody 2.0ghz that will not power on or charge using the charger. It will power up just fine with a charged battery though. Opening it, I did find that fuse F6905 was burnt out along with Q7000 burnt and the ESD one wire pin lifted and corroded(burnt to crisp). The DC jack was shorted to smithereens because the aluminum case touched the the bottom the DC jack circuitry (This was all caused by the Macbook was dropped and the lid was bent in, touching the jack).
Now looking at the repair, I did have a donor board available to repair some of the SMD's that were clearly burnt. I replaced the DC Jack, repaired the burnt traces, test continuity of the traces, and reflowed the Q7000 and C6905 Cermamic Cap onto the board with solderpaste, double checked the contuity and tested the fuse and all that shows ok. After testing the board it is still showing the same symptom. No Charging, No Charger Light, and can only be powered via Battery. Any guess on what may lead me to the root of this issue? You guys are awesome here with all the previous help thank you. And I'm still learning a ton here (more so than other places.) So kudos!!
Esta é uma boa pergunta?
If a Schematic and pictures help I can also include those. But I'm aware most of you have a schematic.
por Justin Aka Taco
what is your voltage on either R6905 or pin1 on D6905
por oldturkey03
I'll find out today and post.
por Justin Aka Taco
It's showing roughly 16.7v and that's measured from the top most side of it.
por Justin Aka Taco
Wierd, on the U6990 I get no voltage at all to the (PPVIN_G3H_P3V42G3H) top left pin and (PPVIN_G3H_P3V42G3H) third to last on the left either. No Voltage is passing through either sides. Which possibly means that something before it is causing this. So I back trace on the schematic by one component before U6990 and find D6905 as a diode (Maybe, I don't know :P) that converts branches BATTERYPOS and PPDCIN_3G_P3V42G3H to one separate trace (PPVIN_G3H_P3V42G3H) that goes to U6990. I check the voltage on the top pins and they all show 8.7v and all the bottoms pins that should go to U6990 do not have any voltage. My guess here is that D6905 is retired and needs replacement.
btw. I checked C6950 and it's showing 3.4v.
por Justin Aka Taco
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