A MacBook Air M1 came in from St Andrews on a Monday morning in late October, booked in for a diagnostic. It was the 2020 model, the A2337, with 8 GB of memory and a 256 GB drive.
Within an hour and a half we had it open. On the M1 Air, the two USB-C ports don’t sit on the main logic board. They share a wee board of their own at the left side of the case. We lifted it out for a proper look. Both ports were corroded. You can see it in the photos: patches of brown, black and greyish white on metal that should be clean and bright.
Corrosion is what happens when moisture sits on metal, and power running through a port speeds it up. A USB-C port has 24 tiny pins. Before a charger steps up from 5 volts, it has a quick chat with the Mac over a couple of those pins to agree how much power to send. Corrosion can spoil that chat. On the power pins it adds resistance, and resistance means heat right where the plug sits. Once it has eaten into the metal, no amount of cleaning brings it back. New ports were the fix.
We sent the quote over that afternoon to replace both charging ports. The customer said yes. We also told them to replace their charging cable. When a port is damaged, the cable that’s been plugged into it can be damaged too, and a tired plug can go on to harm a brand new port. A new 60 W USB-C cable went home with the Mac too.
With both ports replaced, the Mac was ready to collect at 4:37 that afternoon. Same day. Our laptop test had flagged one more thing. The battery was holding 79% of its original capacity after 632 charge cycles, so we noted it as due a service. A battery at that level still works. It just won’t last as long between charges as it did when new.
If the ports on your MacBook look discoloured, or charging only works with the plug held at an angle, get it looked at before it gets worse. Swap out any cable that’s been living in a damaged port, keep drinks and wet hands well away from the charger, and never dig at a port with a pin, a paperclip or anything else made of metal. A soft dry brush is all it needs. Drop it in and we’ll take a look.
Need the same repair? See our full MacBook Charging Port Replacement Dundee | Repair Alliance service for pricing and what's covered.
