Why 4th Pin of Lightning connector turned black? [Understanding]

Yet another post inspired by “amazing” quality of Apple’s lightning (and not only) cables. In one of my previous articles I already mentioned some common issues of lightning cables, but recently I came across another one… So today we will try to understand why one of the Lightning connector’s pins turned black.

Why would you even bother with black pin? Because you cable stops working then… to be exact, one side of cable connector stops working.

What’s the reason of a black pin?

To be honest there is no clear answer for this question. So far we can only guess and try to explain it from technical perspective.

lightning connector pins meaning

Looking at the schematic above, makes it clear that pin #4 of lightning connector corresponds to pin #5 of lightning socket, which is POWER. Most likely when you plug the lightning cable into the device, a short glow arc occurs (or spark, if you want), which scorch the thin contact layer.

May be it’s totally OK that a tiny spark appears for a fraction of a second and the problem is hidden in poor quality.

Yes, the pins on the connector are just microns thick.

So what’s the reason? As I said before, there is no ultimate answer. I can just narrow it down to the following:

  • Low quality of original Lightning cables (Yes! They are LOW quality)
  • Third party chargers with higher current output
  • Bad contact inside of Lightning socket (possibly due to dirt/lint)

Looks like the problem does appear only with some devices. But we don’t have much of the statistic.

In my case I blame the third party charger, but not sure about that. A brand new original Lightning cable lasted only 6 months before the fourth pins on both sides turned black.

One more thing to mention… Recently I came across a HUAWEI phone, which had a scorched contact inside of a micro USB port. A colleague asked me to figure out why it wasn’t charging. So here is the clear reason why…

Is it possible to fix?

The quick answer is – “Not Really…

Lightning pin destroyed corroded

It may look like the black pin is just dirty and cleaning with alcohol may help. In reality the pin is gone… burned, scorched, corroded, destroyed… There is no pin any more. It’s just a tiny line of ash.

The solution is to buy a new cable. Most likely new original Apple lightning cable will be destroyed the same way. It’s just the matter of time. Sorry Apple – your cables suck!

I found a perfect replacement though… For last three years I’ve been using Lightning cables made by Ugreen company (I buy from here). With these cables I never experienced an issue of black pins, neither had any physical damage or failing chip. It just works like AK-47. Recommend!

That’s all for now. Stay healthy. Do some sports. Drink beer.

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