Ahh... the pain .. the agony.
I can understand your situation buddy as I also had a driver die out on me a few days back. Was head banging on a lil loud volume when suddenly the right side died on me.
Posted about the incident here in forum as well.
Same trial and error in my case as well. Changed cables and sources and nothing worked. Then a day later, the right side did come back to life like a zombie, sounded fine until I raised the volume past mid on Soloist (medium gain about at 80) when the right side again died. This same thing happened a time more and then the right driver finally went total silent.
Dropped in a mail to Hifiman Support and fortunately after a few mail exchanges, my replacement unit was dispatched and I had it in a decent time frame.
Kudos to the Hifiman for customer support but then again I wouldnt want to contact a manufacturer for an equipment failure within a few months of ownership in the first place and that is after paying more than Two Grands for it!
Hard to put Hifiman in what ball park - Good company with headphones that sound great and with nice customer support or a debatable untrustworthy company for bad Quality control especially at the top tier level.
HE1000V2 is a fantastic headphone, for it had me back in smiles listening to the replacement unit but a mere thought -'is it safe to crank up the volume past this point or please dont die out on me this time or what will happen after 3 years when the warranty runs out', ironically spoils the pleasure by a bit and makes me concerned.
*
hits next track and crosses finger - V2 death not today*