Is our house killing our MacBook chargers?

July 13, 2012 9:11 PM

In the past year or so, around four MacBook chargers have basically stopped working (I've lost count as this includes a couple of old chargers from early MacBooks we had lying around), all in mysterious fashion. Generally they overheat more than I think is normal, and often they switch to the dreaded, "Not charging" status. On one of them, the rubber insulation melted completely then buckled. I am wondering whether it's just a coincidence that so many chargers have died, or if the wiring in our old house could be to blame?

The chargers that have broken down are:

* 1-2 old MacBook pre-unibody chargers
* 2 new-style MacBook unibody chargers

The newest one, which we bought maybe a month and a half ago at a Best Buy, is started to behave irregularly too. Just this evening it was getting very hot and was refusing to charge.

Many, actually most, of the sockets are not grounded. In addition, I'm fairly certain a few of them wire wired badly. When the house was inspected it was discovered that many of the "grounded" outlets were nothing of the sort. An electrician later came in and switched the non-grounded 3-prong outlets with 2-prong outlets. There is one outlet in particular that is obviously new, and was installed when grounded outlets was the norm. This was one of the faked "grounded" outlets. There's evidence that whoever rehabbed the house (and sold it to the owner before us) did a genuinely shitty job on many of the areas of the house (for example, there was an are of drywall that was just attached to one board and not framed at all).

Tomorrow I am going to the Apple Store to have them look at the newer chargers (they are a year-or-so old). I have the 3 year AppleCare warranty for my computer (but not my wife's) so I am optimistic that at least one of the chargers might be replaced.

However, I really don't want this to happen again. Is it possible that something is wrong with the wiring? How would I go about finding this out?

And what, if anything, should I tell Apple when they ask me about the two broken chargers.

When we do finally get an electrician to come in and redo all the wiring (and oh my goodness is that going to be expensive), will that help matters? Would it improve things to use the grounded extension plug with the charger rather than just plugging it directly into the wall with the 2-prong plug?

posted by nosh, daven, shtup to computers & internet (9 answers total)

Once I bought a Macally brand charger, this stopped happening. About $30. Had mine 5 years. Prior to this, replaced with the Mac brand once a year. They are notorious for melting down and causing fires.
posted by jbenben at 9:27 PM on July 13, 2012 [1 favorite]

I would think the only way a electrician would really make a difference is if your other appliances, chargers, etc. also suffered regular failures or showed symptoms of poor wiring. For example in our house we can't use the coffee brewer and microwave at the same time or we have to go flip the switches. That kind of thing would indicate more issue with your houses wiring then the chargers.

Also I don't understand why the electrician would replace back the 3-prong with 2... seems like quite a backward thing to do especially when 2-prong are pretty rare (as far as I recall my last trips to Home Depot). Might as well have asked him to spend the money on 2-prong outlets plus whatever to do the grounding in some way instead.

Have you checked Apple's recall pages? I recall charger issues with Macbook chargers a year or two ago on older models.
posted by Bodrik at 11:25 PM on July 13, 2012

Also I don't understand why the electrician would replace back the 3-prong with 2... seems like quite a backward thing to do especially when 2-prong are pretty rare (as far as I recall my last trips to Home Depot). Might as well have asked him to spend the money on 2-prong outlets plus whatever to do the grounding in some way instead.

The outlet was not grounded. Whoever had rehabbed the house put a bunch of 3 prong outlets on circuits that were not grounded. The electrician was hired by the owner before the sale to comply with minimum safety rules since it was a FHA loan. Electricians can only put a 3 prong outlet onto a grounded circuit, which would have been too expensive for the homeowner I guess. We could have made it a condition of sale but I doubt we would have gotten as good a deal on the house.
posted by nosh, daven, shtup at 11:49 PM on July 13, 2012

That's kind of odd. First, I'd try and get Apple to replace all your chargers, not just the new ones. Can't hurt to try.

Second, are you using the appropriate chargers with the appropriate devices? Apple has everything from 45W, for some of the MacBook Air's up to something like 95W for the 17" MacBook Pro. Using a lower wattage adapter with a device that is intended to be used with something higher shouldn't burn things out, in theory, because I'd expect that Apple does something to avoid drawing too much current. Even so, such a mismatch will mean that a power supply spends more time at its limit, which I'd expect would mean it is more likely to overheat and wear out prematurely.

The house wiring could play a role too. If the voltage sags for some reason, it could draw more current. Again, I'd expect a safety cutoff, but too much time at the limit of the performance envelope could lead to premature failure.
posted by Good Brain at 12:06 AM on July 14, 2012

Note that MacBook power adapters are only two-prong, and do not require a ground connection. The detachable extension cord does have a ground pin, but it doesn't connect to the adapter. So, whether your home is grounded should be irrelevant. But what do I know, I'm not an electrician.
posted by Sfving at 7:51 AM on July 14, 2012

Any chance you could get or borrow a multimeter to measure voltage output? Ramping down voltage generates heat. If the voltage supplied is higher than the regulator's rating, damage could occur I'd assume. I'm not an electrician either, but I'd also suspect a dirty AC waveform, which could supply excess voltage over a bridged rectifier within the adapter. (eg. normally AC alternates in a sine wave between both prongs...a bridged rectifier uses 4 diodes to normalize all the positive peaks on one side, and all negative peaks on the other. If you get similar peakes at the same time on both prongs, that could be a problem I'd think)
posted by samsara at 8:20 AM on July 14, 2012

Old house, similar problems. Went through 3 toothbrush chargers and two phone chargers in 4 months before I started plugging all chargers into a surge protector.
posted by Mr. Yuck at 9:47 AM on July 14, 2012

You might try plugging your power adaptor into a half-way decent UPS. UPSes do a better job of cleaning up power than a simple surge protector. Well, that's what the marketing claims. You wouldn't need a big one as the high end power brick is only 85W. The bad news is UPSes require 3 prong outlets.

Also make sure you are keeping the power bricks well ventilated. Since you are plugging them into the wall I can't see how they wouldn't be though.
posted by chairface at 5:39 PM on July 14, 2012

Second the UPS-- it'll condition the power as well as act as a battery.
posted by Sunburnt at 7:22 PM on July 14, 2012