Hmmm ... Device temp is about 55 C. No rejected shares for 24 hours at litecoinpool. But noise from cooler fan is so strong, Does anybody have change cooler or have some ideas about it?
And if i was change core speed down to 52Mhs which voltage i can set for stable work?
I had a bad fan on one of my cubes. Inno told me to replace with any fan CFM >= 200.
You could do a search on decibals per CFM and see if you can find a quieter fan.
Other options include duct-work to feed outside AC directly into cubes, similar to what they did for early AntMiners...