Antminer S9 three fans

[tim-bc]

Any idea why this antminer was showing three fans?

Here is what it looked like:

Code:

Checking fans!get fan[2] speed=6120
get fan[2] speed=6120
get fan[2] speed=6120
get fan[2] speed=6120
get fan[4] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6120
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
get fan[2] speed=6240
get fan[4] speed=1800
get fan[5] speed=1800
Fatal Error: some Fan lost or Fan speed low!

I thought this was rather amusing. I double-checked the miner to make sure it only had two fans, and that they were running at full speeds. A firmware downgrade to April 2017 seemed to bypass the issue. Thoughts?

EDIT: The April firmware did not fix the issue, it still lost the fan. The only solution was replacing the bad fan.

[1715022315]

1715022315

[1715022315]

1715022315

[fanatic26]

Ive seen this a few times with aftermarket fans I have used. For whatever reason some fans read double on the antminer console. I purchased a bulk order of 3000 fans from China for replacements and id say every 1 in 50 does that, no clue why.

[tim-bc]

So you'd say the problem is usually with a fan and not the miner? In my case they are both stock fans, I might swap them out one at a time and see what happens.

[fanatic26]

So you'd say the problem is usually with a fan and not the miner? In my case they are both stock fans, I might swap them out one at a time and see what happens.

Yea in testing when I would swap out the offending fan things would go back to normal so in my experience the fan is doing something to confuse the firmware.