hi AAC community!!

I own a pair of Philips headphones that have USB connectivity instead of a normal 3.5mm jack. I think the model is SHG7980 or something along those lines. my brother broke the USB connector and ripped the golden fingers off of the PCB. I don't have the money for a gold replating kit and where I live there are no shops that can replate them. I'd like to replace that PCB with a TRRS jack, but I do not know where to solder each wire. I have to point out that the headphones have a mic and that there are 6 wires in total. the solder joints connecting the wires to the PCB have little notes that say G, M, MG, R, L and SG, as shown in the photo. I know that the red, green and brown wires mean left channel, right channel and ground, respectively. but what do the other wires mean? and can I connect them to the jack? if so, how do I do it? please note, I am an absolute beginner and please do not be rude, I'm not a native speaker, I do know you care about grammar, I'm trying my best

cheers!

 

...the wires to the PCB have little notes that say G, M, MG, R, L and SG, as shown in the photo.

My guess:
G = power ground, shield
M = mic
MG = mic ground
R = right signal
L = left signal
SG = signal ground, for left and right signals

I believe you can connect this all with the proper plug. Look up the standard pinout for the TRRS jack with microphone. I suspect all the grounds are really the same, but not necessarily.

I'm no expert but I'm a little concerned that this set may have utilized a microphone that is not compatible with the other TRRS sets. It used a USB plug, and that means it could have used a powered system to adapt the mic signal. That "pre-processing" will not be functioning if you connect directly to the mic. Hopefully this is just me worrying over nothing.