Galaxy S7edge is beeping instead of vibrating last night was installed Android 7 Nougat on my Galaxy S7edge, lot of my favourite applications doesn't work with it, so I have download official ROM of Android 6 Marshmallow and downgrade it using Odin (AP file only). Now come the problem, my phone don't vibrate, I hear only very quiet beeping at this moment (time when it should vibrate).

I've already try both "wipes" in service mode, factory reset, other Marshmallow official ROM. No success. But it can't be hardware problem, because when I restart or power-on my phone, it shortly vibrate on startup.

Thx for Your help.

Luke
I have exactly the same issue with non-edge (standard) galaxy s7. I downgraded android 7 to 6 but used all four files from the official firmware (including home_csc file) which actually factory reset my device / erased data. I wasn't that bothered about restoring everything as I was relieved to escape from the awful Android 7 ui design. The vibration issue is annoying  as everything else on the reverted Android 6 is perfect. I'm using official final xeu firmware for Android 6, for my device I believe this is G930fxxu1bpl2.  

Just found this statement in another forum but not had time to look into it further...
THE ANSWER TO OUR PROBLEM IS: We are running a Nougat Bootloader on Marshmallow

Not sure if this is correct as it appears that I have the latest android 6 bootloader G930FXXU1BPL2 (for my standard s7). However it does make sense that something from android 7 could be lingering as we both have the same issue after downgrading from Android 7 to 6.

Please post a solution if you fix yours!