clean iPhone lightning cable to fix intermittent charging

Fix Lightning Cable Burnt Pin Black Line

It is important to notice if there is a black line on your lightning cable or burnt pin and clean it. That black stuff on the iPhone charger will get worse over time and cause charging problems. It might not necessarily be the pin that is burnt, as you will see. That means you can recover it. If you see your iPhone charger turning black, you can take action to recover it before it causes charging problems. At the same time, you should clean lint from the iPhone port. In the worst case with no action, your iPhone charge will not charge at all. This can save you buying new cables (or phone) before their time, so read on!


Why does my iPhone Charger Cable Have a Black Line on It?

Fix Lightning Cable Burnt Pin

Black Stuff on iPhone Charger

Remove lint from iPhone Charging Port

How to clean iPhone charging port – Part 1

How Else can I Clean my iPhone Charger port – Part 2

Why does my iPhone charger have a black line on it?

A black line or black spot on your charger is caused by a burnt pin, or rather black soot burnt onto the pin.

We can and should fix this, before it gets worse. Lets take a closer look.

Fix Lightning Cable Burnt Pin

To fix a lightning cable burnt pin, one first must determine if it is the pin is really burnt or it just looks burnt.

Typically the pin is not significantly burnt nor damaged. Instead, the black lightning pin is caused by black stuff, from the iPhone port. The lightning port is like a little pocket which catches stuff from your phone’s surroundings.

If you fix and remove the black stuff before too long, it is likely you can recover your cable and prevent the actual burning of the pin itself.

If you have left it a long time or it has happened very many times, you might well suffer a true burnt pin. Sorry, but in that case you will require a new lightning cable.

Try to clean it first to save the cost!

You may ask, “why does my iPhone charger have a black line on it?”

The reason is carbon deposits, like soot. 

Yes, that charger black spot is burnt remains, mostly carbon. In most cases it is a build up of burnt remains, rather than the cable pin actually being burnt. It’s explained more below, then help you fix it.

See just a little further below for the cleaning method.

Black Stuff on iPhone Charger

You may ask, “why is my iPhone charger turning black?”

There is some black stuff coating on it over time. But what is it, and why is it there?

The black line or black stuff on your iPhone charger is typically burnt lint from your jeans pocket or other clothing. It can also include oil from hands that occur naturally on our skin and hands.

It can be a combination of these things.

The lint in your jeans or clothes is mostly cotton, and so what is burnt on is mostly carbon.

The black stuff on your charger can even be burnt on food.

The reason why these items create a black line, is as follows.

The charger has several pins and these serve different purposes. Stuff like data transfer and power supply move through different circuits through the cable and different iPhone charger pins.

iphone charger cable black mark

Black mark on iPhone charger pin. See pin 4 from left.

The black mark is on the iPhone charger or power-supply pin.

NOTE: technically you count pins from the left when facing the iPhone charger cable, so technically it is pin 5.

The key pin of interest with the black stuff on it is the charger pin that transfers the power during charging.

Why is a gold pin on my Charger turning black?

In a light with a separate switch, the power arcs within the switch of the circuit, nowhere else. Engineers design the switch so it can continue work with that arcing for many years.

In your iPhone charger circuit, the power can go through from your charger to the phone as soon as you push the power cable into the lightning socket on your phone. This will happen if the charger is already connected to the power supply when you plug it. As the pins with electric potential (under-charged phone and power supply) approach each other physically, an arc or spark can occur as electricity jumps between them.

This happens a lot because most of us leave a charger plugged in next to the bed or table at home. Most of us have a kind of dedicated charger location.

NOTE: ‘arcing’ is when electrical power jumps across an air gap (or other stuff in that gap) between metal electrodes just prior to the metal being in contact. It can burn the stuff between. In the extreme example, an arc welder uses arcing to burn or melt metal to fuse it together!

When your iPhone charger is turning black, repeated arcing is causing more stuff to be deposited on there and burnt on there. There is a build up of black stuff on the charger port.

As mentioned above, the power goes through one pin, so it is that lightning pin that the iPhone charger black line develops on.

Why is the pin turning black over time?

The lightning cable burnt pin gets worse over time, because more lint gets burnt on over time.

In addition the black soot can act to resist charging, creating more powerful arcing. This then burns on more lint etc to the pin.

Luckily you can see where all this is going. You can fix the intermittent charging that can be caused by cleaning the lightning connector and inside the iPhone charger port.

Here’s the Actual Cleaning Method:

Scrub the end of the lightning connector to clean it, with a gentle cleaning solution.

Just wiping the end will not be very effective.

Rather than use abrasive material, use something soft like cotton or a Q-tip.

NOTE: Make up a cleaning solution of weak soap, strong vinegar and/or lemon juice, in water.

The soap will help dissolve and remove any oils present from hands or skin. This can weaken the soot structure.

The gentle acids in these liquids will help eat away and dissolve the carbon or black stuff.

Be prepared that you must rub and scrub for a few minutes. You should stop to check progress every so often as you go.

Warning: If you notice any loss of color from the adjacent pins – Stop!

You have done something too strong.

Remove lint from iPhone charging port

It is also important to remove lint from your iPhone charging port.

Over time lint and other debris fall into or get rubbed into you pocket that is your iPhone charger port.

When you push in your lightning charger cable, it gets a little more compacted each time.

It can get bad enough so your lightning cable won’t stay in your iPhone to charge it.

O-oh, no more battery!

How to remove debris from charging port:

To remove lint or other debris, you need to physically scrape it out.

You want to scrape it out with something harder than the lint or debris, but softer than the iPhone connector pins.

Remember the lint can be packed in quite hard when you repeatedly push in your lightning cable like a ram!

A toothpick often gets the nod.

The wood is thin and small. In that form it is relatively soft and a little flexible.

It is still harder than most link and other debris the iPhone charging port can collect.

Use a toothpick to gently swipe up and into one edge, then across and then retain at an angle and withdraw to scrape out anything that might be inside the charger port.

How to clean iPhone charging port – Part 1

You can do something similar without a toothpick.

You will need something that is similar in size to the hole in your iPhone for the lightning connector. It’s surprisingly narrow!

Try one of the following.


A Q-tip can work and I often recommended them. I find even when crushed the stems are still a little too wide to fit inside the port.

This means often only the cotton part fits in. This allows you to do a partial clean. It is okay but perhaps not the best way to remove all lint from the port. In fact, it’s better for rubbing the pins to clean them than to remove lint jammed up inside.

I’ve tried to use finely folded paper and it kind of works. It is only strong enough to give a partial clean at best.

A great tool to use to clean iPhone charging port without toothpick, is a twist-tie.


By twist-tie, I mean those plastic-coated wires that we use to twist around other things to keep them together. The white ones used on loose parts in toys or cables or other things you buy are okay.

The ones that come with freezer bags are not very strong so are not very good at all.

The best ones are the stronger black ones that are typically on serious quality electrical goods. Including on new USB cables!

Use the same method as explained above for the toothpick, but of course you do it without the toothpick!

In fact, it might be better than a toothpick because you can bend slightly the end to make a tiny hook.

See my photo below of the lint removed during a successful clean.

This is how I got lint out of iPhone charging port without a toothpick.

I had no toothpick, but I did have the black twist tie wrapped around my new charger cable when it arrived!

Cleaning iPhone charging port. – Photo shows the lint and black stuff I cleaned from my iPhone charging port without toothpick. I used the twist-tie that came with my new iPhone charger cable!

My choice of iPhone charger cable?

I bought this iPhone charger cable and found the two cables to be awesome with a very robust design, and I’m really happy with them.

TIP: Look for something that is going to protect the cable near the ends as that is where they fail in a way you can’t easily fix them.

Note: the above link is an affiliate link and if you click and buy one and it qualifies then I’ll probably get a tiny fraction of that. Which is to say (with the price of a charger cable), almost nothing, lol! You can use that link to get started and find your own that you like.

How Else can I Clean my iPhone charger port – Part 2

Along similar lines to Part 1, there are other small plastic-only items you can use.

A great one, though not always handy, is a ‘cable tie’.

Cable Tie

I’m referring to the plastic ones. Do not use a metal one! A metal one will be too hard and may permanently damage your iPhone port. Not worth it to just clean out some lint or other stuff!

A cable tie for those that don’t know is a narrow plastic strip with a step pattern on one side, and an end that it zips into. People clamp cables and hold other things tightly together using cable ties very often.

These come in all sorts or sizes and variations.

You can typically cut them with good scissors and strong force, or a knife.

The method is the same:

Push it gently up into one end.

Drag it along the inside of the port.

Hook out the lint at the other end.

Repeat a few times, including from the other side.

After Removing Lint, Clean the Connector Pins

Once you have removed lint, then clean the iPhone lightning cable.

This is just as important as removing the lint. In fact it might be more important!

Rub the burnt pin or black line on the charger with cleaning fluid.

For detail on how to make a suitable cleaning fluid and what else to use and do, see this article.

Still having problems with charging?

There might also be a build up of black soot inside the iPhone charging port that you can’t see.

It stands to reason that if you get a black line on the iPhone charger pin (one of the electrodes experiencing the arcing process) that you would get similar black line on the inside of your phone. Yes, I mean where the other electrode is in the circuit.

Sure, you can see the black line on the iPhone charger. But you cannot easily see if there is a similar line inside your iPhone charger port. Its probably is there the same as on your cable.

Its important to clean it. I mean, you can throw away an iPhone charger cable with a black line that doesn’t charge very well, and replace it.

But you do not want the counter-part pin inside your phone to become blocked with similar black stuff. You do not want to throw that away and replace it!

Clean it using the method shown here.

Did this article help you? You can also help your friends – so share it!


We’ve explained what that black line is on your charger pin. We’ve showed several ways to clean your iPhone charger port, including with and without a toothpick. In addition to removing lint you will want to remove that black soot burnt onto the charger pin. Some FAQs follow.

Why does my charger have black stuff on it?

That black stuff on your charger is caused by burnt pins, or rather black soot burnt onto the pin. The phone charging port is a little pocket that builds up lint from our clothes, oil from our hands and so-on. Each time we charge there is a little electrical arc which can burn that stuff onto the charger. We should fix this before it gets worse.

Why does my charger look burnt?

When you connect your charger to your smartphone, a little electrical arc jumps between power connectors at the start of charging. Traces of lint and dust, and possibly oil from our hands on the charger gets a little burnt. It gets worse over time, so fix it before it stops working.

Why does my iPhone charger have a black line on it?

A black line often forms on the power pin of your charger. It is caused by a build-up of soot which is burnt on there by a tiny electrical arc each time you connect. Over time it can block the flow of electricity and stop your charger working, so clean it before it gets that bad.

Why do my iPhone chargers stop working?

There can be several reasons, but a frequent one you can fix is that deposits of soot get burnt on the connector pins. It is necessary to clean the charger and phone port to get them to work again. If you don’t clean the phone port the charger pins get fouled quicker.


About The Author


Jeff (Surname withheld for family privacy) is an engineer with over 26 years experience. He first learned to program in Fortran 77! See the 'About Us' for more.