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Connector / dirt fail

Understand, connector designers: dirt and junk will get into fielded connectors. It's a thing; it's not avoidable. It's worse for consumer electronics, which get all kinds of abuse.

So, if your connector plan doesn't allow for dirt and junk, please change your plan. A couple of cases in point… I got a Macbook Air by accident a year ago—my employer gave it to me. The power connector is #$@! encrypted, which ticks me off mightily. That aside, perhaps the worst feature of this connector is one that Keith Packard warned me about in advance, and which I've already experienced two or three times. The fine engineer who designed the connector decided to put a deeply recessed strong magnetic plate in the laptop itself, and a mating ferrous plate in the connector. This sounds like an awesome "quick-release" feature for when the cable gets kicked, and it is. The thing is, though, that magnets (and I know this is surprising) attract ferrous materials from all over. For Keith and I the big one is tiny surface-mount components, but plain old metal filings would be even worse. These things get into that jack and, at best, keep the plug from mating. Because the magnet is strong and the recess is small and deep, no ordinary tool will remove them: you need a tiny pair of tweezers. Fortunately I have those, but who wants to carry them around? Bleah.

Engineering recommendations: Put the magnet in the plug, not the jack. This will make it easy to scrape stuff off when it sticks to the magnet. Alternatively, give up on the cute magnet and just use a normal spring system like everyone else does. Recess the jack less; it's more than it needs to be. Instead of a sharp lip on the jack, use a contoured lip so that stuff can be ramped out.

Micro-USB connectors are ubiquitous. The design has a deliberately engineered improvement on mini-USB that is really nice: the little springs that hold the plug in place are on the plug now, instead of on the jack. This means that when these springs wear out (and they will), you can replace the plug (i.e. the cable) rather than the jack (i.e. the device). However, the little springs on the plug mate with little slots in the jack. The problem is that when cruft gets into the connector, it can fill up those slots. Now you have a jack with the serious defect that it won't hold onto any plug anymore. This happens to me most often with my cellphone, which lives in my pocket and collects lint, and which hangs the cable from the cellphone bracket in my car. This one is a total pain to clean out: you reach into the jack with tiny skinny tweezers and start trying to pull pocket lint out. It's made worse by the fact that the slots are almost covered by a thin plate inside the jack; there's very little clearance.

Engineering recommendations: replace the little slots in the jack with little tabs, with corresponding slots above the springs in the plug. Move the contact plate away from all this mechanism toward the middle.

Yes, connectors are hard, and there are a lot of constraints to try to satisfy at once. In the end, though, connectors that don't tolerate dirt are fail. Fob

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