XT90S questions - popping coming from connectors

Hi there… Am a bit confused on what the XT90S connectors do, and how to use them properly.

I own an off-the-shelf Trampa 2019 pro board. I understand the XT90S’s have a resistor in them to help prevent a spark ocurring, but I’ve had a few issues where they do ‘pop’ as I’m connecting the loop keys. Does this mean they should be instantly replaced? There is a small amount of black charring inside the connector, but nothing overly concerning. Are they also meant to act as a fuse?

Also, when it comes to connecting the loop keys to the board, is it best practise to connect the end with the resistor into the board first, or the other end?

Thanks.

They should not pop. Either they are fake or you may have a loose connector, which may explain the charring.

The male pins concist of 4 parts. Push them outwards a bit using a small flathead screwdriver or something and see if the popping disappears. If not, replace them with something bought from a different store. Having loose pins is at times enough to cause arcing under load causing high Temps enough to fuse the nylon together.