[Nexus 6 Q&A, Help & Troubleshooting] DRatJr:
So I have read about this issue a couple of other times on here, where the device is playing music and it randomly lowers the volume and it may/not come back up to full volume. Well this is happening to me. I can't make it reproduce, but if I throw on some Spotify for a little bit or YouTube I notice it randomly. For me, if I keep hitting the volume up, 5-10 times, the volume comes back up. It's important to note the volume indicator in Android never says it lowered, it says its full. But after hitting the volume up numerous times, it'll come back up. It's also worth noting I don't have any notifications coming through at these times, and my screen has been on so the notification screen that pops up wouldn't be lowering it.

I have done multiple factory resets, flashed to M, to L, flashed different ROMs / Kernels etc, but I always stick to stock. I only flashed those to see if I could get it to go away.

I went to the Sprint store and the tech said he needed to see the issue for him to replace it free of charge. I have insurance, so I should be able to get a free replacement IF its a device fault and not my own. If it were my own I'd have to pay. So here's where the issue comes in. I took it in the first time, and he hooks it up the the Cellebrite machine to see if he can see a fault in the device through that, and it says its rooted (which it was w/ bootloader unlocked). He is cool about it, telling me he is supposed to flag my phone so I can't have it replaced free of charge, but he isn't going to. He said if I come back and it isn't rooted he'd try again. I flash the newest Android M dev preview from factory images (no root) and bring it back in. He hooks it up, and it shows up as an N7 to the Cellebrite MAchine / diag app. He manually selected N6 but it still says its rooted so he can't do anything.

Before I moved I would go to Sprint all the time if I had a device fault (different devices) and that particular store said Sprint didn't care if it was rooted, it didn't matter as per Sprint employee guidlines. But now it seems it does? Neither of these stores (before I moved and now) are corporate stores either. But I know my local corporate store used Cellebrite too.

So I have a couple questions here:

1) Would my bootloader being unlocked really throw the "rooted" flash to the Cellebrite diag app? It had TWRP but was definitely NOT rooted the second visit.

2) I've read that relocking bootloader on 5.1.1 can be a little risky, is this true?

3) And he mentioned that he knew of the issue but since it was "rooted" he couldn't get me a replacement, but that I could try to get customer service phone support to send me one. He said I would need a reason I couldn't bring it in the Sprint store, though.

I didn't buy it through the Play Store so Google said they won't replace it (even though its within the year warranty) but to get Motorola to replace it. The problem there is almost the same as insurance. With insurance, I just pay a $200 deductible and get a new N6. With Motorola, they have to put a hold on my card for like $580, then they will refund all of it but the $25 fee for them sending me the phone first and then me sending it back. (Alternative is me sending my phone in first, but I can't since I don't have an alt phone).

Anyone know a direction I could go?

P.S. Sorry for the wall of text, but its just been a long drawn out process.