Given it’s the t-shooting forum after all, I think we can contribute posts to assist others with repairs (mods please move if there is a more appropriate section this belongs under).
I gave my Q701 to my nephew and he unfortunately walked away from his desk with it on and it promptly got yanked off his head and fell on the floor. Took it apart and discovered that one wire came loose (seems this is a common issue w/the Q701 and similar headphones in this line like K701, etc.) so I created this How To vid to guide one on disassembly and repair: