Hi my MagSafe charger 2 has a black pin is that bad since it won’t charge anymore

That charger is bad. The pin is burnt and one of the other pins appears to be stuck down. Do not continue to use this charger.

You need to check the Magsafe connector on the laptop to see if it has a damaged contact as well. If the contact on the laptop's charging port are burnt too, then you should have the DC-In Board replaced as well.

keven98 wrote:

https://discussions.apple.com/content/attachment/9350f0d2-c639-474b-968d-8625e748eb67

you do not say what exact Mac is this... non-the-less see the reference—

If your MagSafe cable or power adapter isn't working

If your MagSafe cable or power adapter isn't working - Apple Support

Find the right power adapter and cable for your Mac notebook ...

About Mac power adapters - Apple Support

Way Back Machine archive— cleaning MagSafe

https://web.archive.org/web/20180110043529/https://support.apple.com/en-us/HT203207

if you are still under warranty—

Check your coverage

My Support - Official Apple Support

Maybe get a piece of dry but sort of rough cloth and wipe it off. It may just have dirt on it.-