2.2 GHz (Turbo Boost up to 3.4 GHz) or 2.5 GHz (Turbo Boost up to 3.7 GHz) quad-core Intel Core i7 processor with 6MB shared L3 cache.

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Running slow after liquid damage - logic board repair

MB Pro A1398 mid-2014

i7 2.5



2gb gt750M

Machine boots fine but runs slow.

Scored about 1100 in geekbench 4 - single core/ 3000 multi-core.

Same i7-4870HQ cpu in my MSI scores 4300 / 14000.

Anyone seen this before? It does switch graphics but runs at like 25% and won't turbo the cpu by the looks of it.

It's like temp sensor is gone bad, but ueing HWsensors/HWMonitor reports normal temps or the cpu is underfed :) starving..

Reset pram/smc etc. Any feedback appreciated.

Thank you

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Check out the area of original liquid damage for an idea of what is effected; I assume you took a picture of the board before cleaning? Check pages 45-48 of the schematic, especially PBUS voltage sense enable and filter, this commonly causes this issue, but other sensors can also. Check around the SMC too.

Best thing to do in this situation is check for damaged components or resistors which are not measuring right in the original area of damage (even if the resistors look fine, they may have failed).

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Trouble is it was rither cleaned before or very little liquid around board as no sensors tripped red.

There was corrosion on the chip right next to jack port, I believe it was tea spilt as the bottom base has it dried on it...

The battery dots are red... shows battery not connected. SMC needs a check.

Other then that, thanks for the answer! I'll update the thread.


Sometimes these run slow if a bad battery is plugged in, try it without this connected assuming you haven't done this already


Tried with batt disc'd same scenario. Sloppy load boot etc. Managed to install clean Sierra so it is stable but running at 25% speed.

Will look at PBUS and smc thanks


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