Screw terminals, also called green connectors, are connectors found in hotends of Fracktal 3D printers. Screw terminals are also found on the MKS board. But Nozzle connectors have a higher chance of getting burnt.
This guide is made as an assistive guide to help you troubleshoot.
If your nozzle is not heating up/ throwing up heating-related errors, checking the screw connector should be part of the primary diagnosis. Below is a comparison of the burnt connector vs the normal connector.
Normal Connector:

All pins are fine. There is no discoloration, and all pins are stainless, and the plastic around them is fresh.
Burnt Connector:

The encircled pins are burnt. The metallic pins have lost their shine, and the plastic around them has turned brown due to burning.
The burnt connector hinders the flow of current, causing the heating system to fail and errors to appear.