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greedygriscoe

macrumors newbie
Original poster
Jan 16, 2019
3
0
The North
Hi all,

Some very strange charging symptoms with a pair of MacBook Pros. Hopefully someone out there has experienced something similar and can shed a little light on it...

It started that fateful day I plugged a quality third party charger in to my work Macbook (late-2015 model). It's probably worth mentioning that the third party charger has been used for a couple of years on various machines and has always performed fine. The MagSafe sparked a little as it made contact, which I've seen before many times on many machines over the years, but this seemed to instantly flatten the half-full battery. Dead. Nothing.

In the hope to establish whether the charger had fused or it was in fact something more sinister, I regretfully grabbed my own fully-charged MacBook (late-2011 unibody) and tried the same charger. Exactly the same story. Small spark, laptop unresponsive, battery indicator showing nothing.

First port of call was to try some genuine Apple chargers. Tried 5 working OEM chargers from around the studio. None were showing amber or green lights when plugged in to either of the machines in question. Strangely though, the third party charger, that I suspect caused the problem in the first place, started charging both machines when plugged back in. I then tried another third party charger that I had to hand and this also charged both books just fine. This seems very strange when both chargers have the very same voltage, amperage and frequency output as the genuine chargers.

After doing some research I read the small transistor on the MagSafe DC Jack Board can burn out as a first form of defence against surges, etc. This had indeed burnt out, so ordered and replaced the part on my 2011 model. Unfortunately this made no difference. Both third party chargers still charging fine but not recognising any of the Apple chargers.

Sooooo... What the hell can it be??

Is it as simple as some feature in the Apple chargers know the book has had a surge (or similar) and won't deliver power? If so what can I do?

Is it a similar feature with the battery or SMC that won't receive power from an Apple part?
nb. I replaced the battery with a genuine Apple part only a couple of months ago and the health seems tip top as far as I can tell from the stats in System Info.

Is it something really condemning - a fault somewhere between the MagSafe DC board and battery on the logic board? I know little about circuitry, but using a map followed the path from the MagSafe board to the battery and back a few times, and can see no corrosion, discolouration, or signs of heat or water damage. I understand this doesn't mean a lot but it's the most I could do.

It's maybe worth mentioning that I tested the voltage of both third party chargers and a host of our Apple chargers. All reading very similar to one another.

As you can imagine I'm totally stumped. Thought I would give it a post on here before sending it off for diagnostics. Hopefully someone can help.

Thanks in advance!
 
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How did you use the same charger on a 2015 MacBook (MagSafe 2) and late 2011 (MagSafe 1)?

I've never heard of Apple approving third party chargers for their MacBooks here in Canada. Do you have a link?
 
voltage is not everything, middle pin of MagSafe is for data to communicate charger with logic board (SMC and ISL are key chips to manage battery charging), some cheap/dodgy replacements don't have a real MagSafe, so there is no data on middle pin, they are risky to use and there is a possibility to damage the logic board
 
Yeah I had read that. To be honest though both third party chargers are neither cheap nor dodgy, and as said worked with no problem for quite some time.

If the middle pin is at fault on either or both of the third party chargers, why are they the only two that will deliver power to the battery? And why are the rest of our Apple chargers, that work with a host of other MacBooks our studio, failing to charge them?

Are there means of trouble shooting further, or is the next step to try a new logic board? Can anyone recommend a specialist in the UK that could diagnose before I have to spend £hundreds?
 
The Apple chargers have a lot of protection circuitry built into them which leads me to believe that they are not turning on or charging the because they are detecting some sort of electrical fault in the Macbooks' charging circuitry. I'm not 100% sure and may be totally wrong.
 
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