Unknown Wiring Cable
Unknown Wiring Cable
The LED isn't working because the connector pins at the end of the cable are touching metal or conductive material. It seems you removed it on purpose. If it was an accident and you want to reattach it, it should be possible since it isn't soldered directly. Just be careful with the positioning, as it might be tricky. You may need to take out some components from the case, such as the HDD cage.
I believed it was a crucial wire and that the connectors made contact with metal. I took apart the HDD cage to confirm there wasn’t a danger. The item turned out to be a light. Should I reinstall it?
You don’t seem to need it unless you’re after that LED to turn on. I’m not sure what connector they use for the cable—if the pins are exposed, covering it with a heatshrink could help because it will be more flexible now.
Eh. Not a fan of LEDs and RGB. Here's what the pins look like.