Chosen Solution
Does anyone recommend disassembly of this device or can I send it back to Sony?
I found them to be quite easy to take apart with a bit of filling with a credit card similar to the newer xm4 disassembly guide. Sony WH-1000XM4 Battery Replacement - iFixit Repair GuideI unscrewed the outer cover to inspect the main board and found no visual damage. However upon adjusting the cable inside the ear cup and removing the protective tape in the central terminal I was magically able to get the left hand side working. during this time I had the headphones powered off with music playing from my laptop through AUX.So if anyone else has this issue I recommend disassembly to have a fiddle around with the internal speaker cable.
