Jack cable repair, 5 WIRE?

Hello,

My headset has broken down (loose connection near the jack plug), so I decided to repair it. I had already done this type of operation quite simply on earphones before, but the situation is different this time.

I cut my cable higher than the jack plug and then stripped it. Surprise, there are more wires than expected...
I thought there would be wires for left, right, microphone, and ground... However, here is what I have:
- one RED wire
- one BLUE wire
- one GREEN wire
- one wire with a WHITE insulation
- one COPPER wire
What is this white wire? (there's no insulating paint like the usual others, but rather a mini plastic/fabric sheath on it).

I took earphones with a microphone that I no longer use, I performed the same operation (there I have my 3 colors + the copper).
A lighter to remove the insulating paint and then "twist" the wires by colors. But there's no sound output...

How should I proceed?
- Photo of the wires: https://ibb.co/XSB0CjM https://ibb.co/GnDmprG
- Headset in question: https://www.ebay.fr/itm/Turtle-Beach-Ear-Force-PX24-Amplified-Gaming-Headphones-Wired-PS4-PC-Read-Desc-/153248169005

Thank you in advance for your valuable help!
Vincent