u/Merfius101

I recently bought a used dt 990 pro, when I tested it the sound is very quiet and there is almost no bass, the seller gave it to me for free because of this so now I’m trying to see if I can fix this. I used a multi meter to check the resistance over the coils and the right one shows 250 ohm but the left one gives 500 ohms. Quick search online says that it’s a busted ground wire but I have no clue how it is supposed to be soldered anyway. I’ll add some pictures for clarity. I do have the tools to try and repair this (soldering iron, desolder, enough small cables and some tin) but I don’t know what I should replace and where I can buy a new cable (if that is busted)