AvalonMiner 841 fan issue

[eissug]

Do I have the first bad 841?  I’m thinking the fan or control board is bad. The fan sounds like a child with severe ADHD is cranking the fan speed up and down constantly.  The temperature on the outlet was reaching 94C and I read that these miners have a target of 70C, unlike the 741...so I unplugged it.  It was doing a normal 13.5+TH/s.  The fan speed was set to 100% and the readout in CGminer would vary between 3000 and 5000RPM, although it only seems to update every 5 seconds so it depended where the adhd kid had the speed set when the info refreshed.

Sound familiar to any other 821 or 741 issues?

[HagssFIN]

If you have set the minimum fan speed to 100%, then it should be running full speed all the time.

For me it sounds like the cooling fan is faulty.

Do you have any spare fan that you can test with it?

[Steamtyme]

Which way is the air exhausting out of the unit? I don't have an 841 but I think they still exhaust the same as the 741, air leaves on the fan side.

I remember a few units that had the fan installed backwards, from previous generations. Now it doesn't explain the fan RPM changing especially if the speed is set at minimum of 100. EDIT: although the backpressure from pushing through the unit as opposed to pulling through might affect the RPM that the fan can spin at.

Just something to check on before swapping fans out. If it is the fan it's a simple fix of removing the shroud and flipping it around.