Mid 2010 Model A1278 / 2.4 or 2.66 GHz Core 2 Duo processor

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How to deal with an IP0R sensor problem?


First, sorry for my so-so english... ;)

I got this A1278 Macbook Pro 13" Mid-2010 from eBay, water damaged, no power (but green light), very clean body, for a ridiculous price... I thought I could give it a shot! It has the 2.66 GHz Core 2 Duo processor.

I disassembled it completely, gently brushed every square inch of the logic board with 99% isopropyl. New battery, new thermal paste... and then, I got chime! Yay.

And then, bam... It just shuts off without any warning. When I hold the power button (maybe 6 or 7 seconds), it will boot correctly. I was able to install OS X, and everything works fine, in fact I'm using it right now to write this post.

3 things are bugging me :

1. It will sleeps, but on wake up, the desktop appears with my apps and the Macbook shuts off only couple seconds after I lift up the lid;

2. I have to hold the power button to POST;

3. When I first ran OS X, the Macbook was very, very slow. I looked up Activity Monitor and a kernel_task was consuming 160% of CPU. I did found a solution on another forum, which was to remove (backup) the file "MacBookPro7_1.plist" (/system/library/extensions/IOPlatform.../Contents/PlugIns/ACPI.../Contents/Resources/). No more slow problem.

So I'm stuck with the sleep/powering up problem. I ran diagnostics and gave me an IP0R sensor error (Charger BMON) reading at 9.166A, which is higher than the high-limit of 8.5A... So, an incorrect current reading. When I boot verbose, I get "Previous Shutdown Causes: -79" information, -79 meaning an incorrect battery current reading.

I'm so close to have a perfectly good MacBook Pro! Please help me, I'm not quite sure in which direction I should go first to troubleshoot this.

Have a nice day and thank you!

Answered! View the answer I have this problem too

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Will be related to the logic board. If you don't have the tools and experience to microsolder, take it somewhere. If not, grab a schematic and board view for 820-2879, and check the bottom of page 44 to find the current sensing circuit for BMON (battery monitor).

Check out these components using the board view to find out what is wrong. Measure voltages, check continuity, measure resistance, etc. Unfortunately we can't hold your hand through this process, since every board issue is different, but hopefully this points you in the right direction.

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Thank you :) I found exactly what you said (schematics page 44 - Battery (BMON) Current Sense, MUX & Filter) and I'll take a look at it!


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