Just wanted to share a bit of good news that happened to me today (and for anyone that has an old Antminer R4) this info could potentially help.
I had an unexpected good event happen on one of my miners today - my old Antminer R4 - you see a lot of them processing at half rate (4THs instead of 8THs) because one of the two hash boards 'goes bad'. Well that happened to me over 8 moths ago on my R4 and today after a power brown-out my other miners never missed a beat and stayed online working away while the R4 appeared to be working (with one board @ 4THs which it has been for the last 8 months and many hardware reboots) but on Kano.is was showing it wasn't processing any shares and hadn't been for over 19 hours. Usually I do a HARDWARE reset by shutting off the main power supply and turning it back on & that resolves the issue. However this time I instead forced a soft reboot in the Miner Configuration Web GUI, and to my surprise - WOW - the 2nd hashing board CAME BACK TO LIFE! Now the old R4 is back to processing at over 8THs! Just thought I'd share some good mining news. Have a good one & mine on with KANO!
I think i saw that happening to me as well once last year, and i think i did in fact just reboot the controller from console.
If you use the firmware from Dec 2018, it should do 8.5THs, or at least it did with my 8T model (600ish mhz boards).