I have been speaking to Yoshi about S4 issues but wanted to get an opinion here since I imagine he is not working on weekends.
One of my units is being shipped back because something burnt. It also had an issue with Fan#2 which is what I posted about earlier.
Looking at my second unit I noticed that Fan#2 in this unit only runs at 240 RPM and the others are about 4000. What caught my attention is other screenshots showing fan speeds and Asic chain temps that are close.
My temps are
chain 1 60
chain 2 48
chain 3 60
chain 4 51
Both of my units have been like this since they arrived. It seems odd to me that both units behave the same way. Anyone else having similar issues? Is there a Fan#2 issue?
BTW - temp in the hashing room is 22C.
Those temps are in line. I wouldn't worry about the the fan speed unless the unit is showing extra hot temps on the LED screen. 68C is about as hot as you want to see. Anything more than that and they may slow down a bit or some chips might shut off and turn to X's. But remember, if you get X's on the chips just reboot the S4 and the chips will all be back to O's. I have never lost a chip permanently on S1's , S3's or S4's.