The hash rate of Antminer S9 is lower than normal.

[sansansan]

I have Antminer S9 (13.5GH/S). Sometimes the hash rate of one hash board falls very low.
http://ipic.su/img/img7/fs/Untitled.1518701512.png

Two other boards always work stably (about 4500 GH/S).
There is no “X” shown on the ASIC status.
I have updated firmware to the latest version.
http://ipic.su/img/img7/fs/Untitled2.1518507242.png

Reboot helps but only for a short time.
What could be the reason?

[1714809796]

1714809796

[1714809796]

1714809796

[castiel0504]

What type of electricity you use? 110v or 220v? And what kind of PSU?

[sansansan]

What type of electricity you use? 110v or 220v? And what kind of PSU?

APW3++, December Batch（HK）
I don't know exactly 110v or 220v (I use colocation). I'll write to the support, I will clarify.
I have another miner of the same batch, located there, there is no such problem with it.

[SGMPhil]

I have seen the same thing with one of mine. I have not been able to figure out what is causing it, but a reboot fixes the problem. Could be a failing board, I just don't know yet.

[sansansan]

What type of electricity you use? 110v or 220v? And what kind of PSU?

APW3++, December Batch（HK）
I don't know exactly 110v or 220v (I use colocation). I'll write to the support, I will clarify.
I have another miner of the same batch, located there, there is no such problem with it.

Support said electricity on miner end was 208v. My other miners are currently on the same circuit. I think there is no issue with electricity.

I have seen the same thing with one of mine. I have not been able to figure out what is causing it, but a reboot fixes the problem. Could be a failing board, I just don't know yet.

Reboot helps, earlier for a day, then for half a day, and now the problem appears anew very quickly after reboot.

[fanatic26]

Try an older firmware. I have recovered hundreds of miners with issues by rolling back the November 17th firmware, it has a lot of problems.

[sansansan]

Try an older firmware. I have recovered hundreds of miners with issues by rolling back the November 17th firmware, it has a lot of problems.

I have tried firmware
Antminer-S9-all-201705031838-650M-user-Update2UBI-NF.tar.gz
and
Antminer-S9-all-201704270135-autofreq-user-Update2UBI-NF.tar.gz
from https://shop.bitmain.com/support.htm?pid=00720161126080548570Q2tDBXAH065D

But the problem persists.

[rymannphilippe]

I have exactly the same problem.

No XXXXX in the Chipscreen, only 000000.
So i think all have to be good.


After a RESET its not always the same.
Sometimes the one low hash board shows 4.5TH (ideal) and always different 0.1 to 1.5TH (RT)

Temps sometimes show realistiv 70 sometimes only 15???
After the last reset only 19 ASIC on the board sho up with 00000.
After another reset all 63 ASIC show up 000000.

My S9 not do more than 9.5TH with all 3 boards...

Im on 230 Volt SWISS Power and tested only the low hash board.
Its not a power problem.

Any ideas or any help.

[BitMaxz]

It looks like your one of the hashing board reach the high temperature protection that cause of hashing drop.
I think you can solve the issue by adding cooling devices and replace the cable of 3 hashing board then test them again and monitor if the result still persist downgrading could be possible to fix the issue if all methods won't work one of the hashing board is damaged and it needs to replace a new hashboard or if it's still under warranty then you can send them back to bitmain.

Try follow this guide https://bitcointalk.org/index.php?topic=3239820.0 and this guide https://bitcointalk.org/index.php?topic=2690140.0
increase frequency then increase the  fan speed of the miner then monitor again.