Topic: antminer s9 fan direction is wrong? (Read 419 times)

i don't know what was wrong with the one my client had, i asked him to flip it, he said when i did, the grill was touching the fan and it would break it, i didnt' go into much details with him, just sent him a spare / replacement fan.

if you mean the one i had, yes it probably had bad bearings, i do work a bit with cnc router motor and i know what a bad bearing feels like, it's like you need much less force to spin it with a finger than a fan with a good bearing would. also the center of the rotation was not perfect, aside from the bearing issue it would kinda float up and down when you spin it, you can't see that clear as day but you can feel that it's wiggling while spinning. not sure that makes a lot of sense but i am sure you can get the hang of it.

that fan caused the miner to drift like a fine BMW.

Im wondering if that fan already had bad bearings because I have had probably 25k bitmain devices pass through my hands and never had a fan that hit like that that also didnt have another issue

I haven't had the issue with my miners, but one of my clients couldn't simply flip the fan , because the other side of the intake fan was not flat enough to fit the the grill , so i had to send him a spare fan.

i also once had a brand new miner that vibrates like an old nokia mobile, it would even jump of the rack , turns out the intake fan motor was faulty, i could manually spin it and feel the instability of the rotation. so you are 100% right , bitmain will just attach whatever fans at their disposal most likely the cheapest ,as i personally have seen a dozen of different fans from bitmain too.

Bitmain uses whatever cheap fans they can source locally at the time. I would say I have at least 8-9 different fan types in my datacenter. They also are not always the same amperage either, the quality and specs can vary pretty wildly and i have confirmed some major flow differences between models. The only criteria i have seen is the rpm range, they need to be able to reach 6000 rpm because that is what the firmware expects and changes voltages to change speeds based on that assumption.

So there is no big mystery. Its just a company buying a disposable part from the cheapest vendor whenever they order. There is no secret or special reasoning for it.

P.S. After attempting to translate what the OP was talking about, it looks like he could have fixed his problem just by flipping one fan around. Yes sometimes from the factory they are backwards, sometimes from the factory they are plugged in backwards on the controller as well. Its not a big deal and certainly not worth complaining about, it takes less than 1 minute to flip a fan around and doesnt touch the warranty stickers.

check this datasheet out:

https://datasheet.octopart.com/V12E12BMM9-53-Nidec-datasheet-505679.pdf

The last 2 digit denotes - Monitor / Controls Options.

I had my S9 with "-07" front sucking fan (speed stable fan), and "-57" rear blowing fan (free running free)
No wonder the Front always has its RPM adjusted, and rear normally does not change much.

Ahm... both fans blow in the same direction (they have to...) so switching the front and back fans would NOT result in one of the fans blowing the wrong way. All fans blow towards the side which has the label. E.g. if you are looking at the front of the miner, you will see the label on the fan and it will blow towards you. The back fan is ALMOST the same type (there is a slight difference) but it also blows towards the direction of the label, that's why you don't see a label on the back fan (it is on the inside, facing towards the guts of the miner).

If a fan blows in the wrong direction, remove it, turn it around, screw it back on, and it will blow in the right direction.

For those interested in the details, the latest S9s have slightly different fans front and back. I have no idea WHAT the difference is, but the front fan is NIDEC UltraFlo W12E12BS11B5-57 and the back one is NIDEC UltraFlo W12E12BS11B5-07 (note the last two digits). Both are rated 1.65 Amps and I see no visible difference between them. But if they took the effort to install two different fans in each unit (which means more complicated logistics), I'm sure they have a good reason for it. I can't find specs for the fans anywhere. If anyone has any info (or even a theory) about the reason for the different fans, I'm curious. Maybe different RPM at the same voltage to make it possible to feed them the same voltage and still maintain the slight pressure difference?

As I understand it, the S9 considers each of the three hashboards as a different "chain", chain[5] is on the right, chain[6] in the middle and chain[7] on the left, corresponding to the J6 J7 J8 connectors. These chains are treated independently. However, it seems all of the chips on a single board are chained together in series, with 63 per board. The miner status page simply splits the number of chips it detects on a board into groups of eight for visual reasons, but they are still all in one long series. (I think)

Yeah been spending a sick amount of time with these buggers( actually been a little incommunicado on the forum because of it). Maybe it's just me but there chip quality is wildly inconsistent.

One thing I haven't been able to figure out yet is how in the web interface it shows the each hashboard as several different chains but electronically I can't find any difference, it just seems to be one long chain. Perhaps it is a folly to assume that each chain is independent, has anyone seen a working chain between two bad ones? Maybe the chains just fail from end to beginning? ( I'm not a miner, the only boards I receive are total failures lol)

Just FYI...sending an S9 back to H.K. from Quebec by DHL now costs $CDN 400.00...That is about 35% cost of a Brand new unit with PSU...(And it comes with ANOTHER DEAD HASH BOARD which will need to be sent back)

I've got two dead boards on units with two weeks left on warranty
A brand new 14Th with a dead board
A brand new 14Th that only does 13Th...tough choice to get them fixed or just buy new ones and keep the defects for spare boards when then new ones die.

4 out of 28 S9's had issues of the last six months

Needless to say I have given up on Bitmain's SHA256 Asics and now buy Nano 8's. and some Innisilicon/Dragonmint

what did you mean here? i have a lot s9 only 2 of them made trouble and im sure not took wrong fan because 2 miner was at 2  different location.
Yes i paid attention warranty seals are gone how to take from good one ??
man this guy has eagle eye lol thanks by the way I was about to sent idiots put front fans to both sides I guess. SHITMAIN

The long bolts on the fan housing are not warranty protected just flip one using those bolts.

Definitely send it back to them. Use the warranty because it's available. It will likely cost you more than the shipping tonget and repair it.

It sucks sending the whole thing back but as i found out you have to play by their rules. The mist theyll let yoy do is open it up and troubleshoot it for them.

Do you mean that there is no intake air and both front and back is exhaust fan?

Did you tried to reverse the fan without reversing cable?

I suggest you better to send it back to bitmain so that they can replace it with new hardware just make sure that it's still underwarranty.

Hi all almost same topic i saw but it is locked that topic is about whic fan must run faster
here it is https://bitcointalksearch.org/topic/antminer-s9-fan-direction-2822051

mine is I guess QC fckd up because both fans sucking air from miner doest matter if switch fron to back because fan direction again both suck from miners.
As may 2018 bitmain ask for the entire miner to be sent i hope warrant seal removed not an excuse to not fix under warranty,
2 hashboard wasnt hashing at all and this miner not even used.

fan arrows are both towards suck air from miner ?? is this factory installed a wrong fan or what?
should sent to bitmain i already opened too see which hashboard i should remove but here we go notice this.

Fans directions are wrong both is front fan insatalled
https://imgur.com/a/yFxhOnS

2nd fan
https://imgur.com/a/IKnrxrG

outside side of fan
https://imgur.com/a/Yh6NArM

inside of fan
https://imgur.com/a/77YTM3m

entire miner if you pay attention switching fan front to back doesn't change it is will suck from miner again
https://imgur.com/a/6T8drIq

it looks like at factory both front fans are installed by mistake.
i tried with normal fans nope 2 hashboards dead should I sent to shitmain or just wasting time trying to fix boards ??