No fan detected in SuperMicro SC846

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Defcon1

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Chassis is SC846-R1200B. I replaced all 5 fans with Arctic F8 PWM (AFACO-080P0-GBA01). The Arctic fans have a 4pin PWM plug and the fans end up looking like shown in this post - My (near) silent SC847



The fans are all plugged into the MB header and not into the backplane. This is what I used to see before -



However now in the bios there's a brief message like - 'System fan control disabled, not enough fans detected' and in the 'health monitor' in bios no fan speeds are shown. Since I'm using PWM fans why is this happening? The fans all power on so I know the connection is made.
 

britinpdx

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Well, 4 pin PWM pinouts are an industry standard, and keyed so that the connectors can't be reversed, so that's probably not an issue. Possibly the connector on the new fan not in the exact same position as the "original" fan (not necessarily in the X,Y dimension but the Z dimension) ?

I'd be going back to basics ... if you plug the "original" supermicro fans directly to the motherboard are they recognized ? Same for the new fans, if plugged directly into the motherboard are they recognized ? Take the fan housing and mid plane cable out of the equation.
 

Defcon1

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Well, 4 pin PWM pinouts are an industry standard, and keyed so that the connectors can't be reversed, so that's probably not an issue. Possibly the connector on the new fan not in the exact same position as the "original" fan (not necessarily in the X,Y dimension but the Z dimension) ?

I'd be going back to basics ... if you plug the "original" supermicro fans directly to the motherboard are they recognized ? Same for the new fans, if plugged directly into the motherboard are they recognized ? Take the fan housing and mid plane cable out of the equation.
I didn't think of this, I will try it out. Do I need to do this for all 5 fans or will just or 2 also work? If the connectors were not aligned on the new fan, then it wouldn't power on, right?
 

Terry Kennedy

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Well, 4 pin PWM pinouts are an industry standard, and keyed so that the connectors can't be reversed, so that's probably not an issue.
Not really, unfortunately. Compare the -14 and -15 options in this PDF. On -14, yellow is the expected tachometer output. on -15, yellow is a simple spinning / not spinning signal.

Unfortunately, the "technical data" for the fan the OP bought provides almost no useful information. For an example of what useful technical data should look like, take a look at this pdf.
 

britinpdx

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I stand corrected if this is not considered an industry standard.

Per the Intel Industry Specifications for Desktop Boards web page I was operating on the understanding that Intel wrote a specification for 4 wire PWM specs for motherboard implementation, that in general has been adopted by most motherboard manufacturers. Perhaps an Intel standard and not an industry standard (although Intel themselves refer to the listed specifications as "industry specifications", many of which Intel identify ownership).

I have a couple devices that implement "non standard" fan pin outs, but I would consider them to be "proprietary" designs.
The fans in the power supplies used in the Quanta LB4M/LB6M are 3 pin power/ground/tach, but do not follow what would be considered "normal" pinouts for typical 3 pin fans from a general PC/motherboard standpoint.
The fans in the Cisco SG500 switch use a Delta 3 pin fan that is color coded black/blue/red. The blue wire (pin2) is not a tach but a "rotor lock" signal (I presume this is the same as noted by the -15 suffix in the Nidec spec).
Similarly, the fans in the Mellanox IS5023 Infiniband Switch are like the Cisco implementation, 3 pin with rotor lock on pin 2.
 

Defcon1

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I have seen others here use those fans, Arctic F8 PWM, and I don't remember reading that they were non-standard layouts. I'm a little hesitant removing all the mobo connectors for the fans and redoing everything, I thought that replacing the fans would be a simple matter due to the hotswap cages. I will try and connect one fan directly to motherboard and see what the bios says but maybe I need to do all 5? I read the X8DTE-F manual and it says nothing on the subject, it doesn't even mention the 'system fan control disable because no enough fan found' error message.
 

britinpdx

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I don't think you need to do all 5.

Just try to connect one of the original supermico fans directly to a motherboard fan connector, then try the same with and Arcic F8 fan to see which one (or both) is recognized.

If you haven't already done so, you may also want to consider resetting the BMC (it is responsible for the PWM fan control) by removing AC power for about 30 sec to let the "standby" power dissipate. There should be a "BMC heartbeat" LED on the motherboard that blinks to show that the BMC is operating. When the AC power is removed, the BMC runs for a short while until the PSU voltages bleed off. When the BMC LED stops blinking you know that the BMC is off and will reset upon AC being reapplied.
 
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Defcon1

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We have some progress! I connected one of the original fans directly. Bios shows - 'System fan config changed. Fan 3 will be monitored' and indeed, the fan spins at 100% then slows down as soon as bios loads, and inside bios I see its rpm.

btw thanks for tip about BMC, somewhere else I read you have to use IPMICFG to reset it and I didn't know how to do that.

So does this mean the Arctic F8 is not a true PWM fan, or its not a standard 4pin? I'm at a loss now, everything I read says they are used by many people for this chassis and they come recommended for this purpose. Anything else I can try? I spent $45 on these and they can't be returned :(
 

i386

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I have seen others here use those fans, Arctic F8 PWM, and I don't remember reading that they were non-standard layouts. I'm a little hesitant removing all the mobo connectors for the fans and redoing everything, I thought that replacing the fans would be a simple matter due to the hotswap cages. I will try and connect one fan directly to motherboard and see what the bios says but maybe I need to do all 5? I read the X8DTE-F manual and it says nothing on the subject, it doesn't even mention the 'system fan control disable because no enough fan found' error message.
I think the Supermicro fans use another connector than the Arctic fans. Arctic fans are made for "normal" cases and are compatible with 3pin connectors on mainboards and don't fit into that extension cord of the fanhousing thingy.

I don't think you need to do all 5.

Just try to connect one of the original supermico fans directly to a motherboard fan connector, then try the same with and Arcic F8 fan to see which one (or both) is recognized.

If you haven't already done so, you may also want to consider resetting the BMC (it is responsible for the PWM fan control) by removing AC power for about 30 sec to let the "standby" power dissipate. There should be a "BMC heartbeat" LED on the motherboard that blinks to show that the BMC is operating. When the AC power is removed, the BMC runs for a short while until the PSU voltages bleed off. When the BMC LED stops blinking you know that the BMC is off and will reset upon AC being reapplied.
If IPMI is available it's possible over the webinterface to reset the BMC. For newer Supermicro mainboards just go to maintenenance>unit reset adn then click on unit reset.
 

Terry Kennedy

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I stand corrected if this is not considered an industry standard.
It is a standard for most of the computers you'll run into. What I meant was that it is not a fan industry standard.

Some computers (normally from larger manufacturers like Dell, HP, etc.) have unusual fan configurations. But since those fans are normally semi-custom parts, it doesn't matter to the computer or fan manufacturer.

If there's some sort of cable between the fan connector and the motherboard connector, "all bets are off" unless you trace the actual wiring on the cable in between them to make sure it is pinned 1:1.

Other pieces of computing equipment (switches, for example) often "do their own thing" as well.
 

Defcon1

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If I have to order new fans I will, any suggestions will be welcome and I'll do my searching.

britinpdx, I've read your post here - Supermicro 846 chassis noise level and seen the SM fan matrix, my chassis came with 3x 95L4 for mid fans and looks like 94L4 for rear.

The other option is to just let the F8 fans run as is without bios control? Are they running full speed if the bios can't detect them? Because they are not loud. The airflow is a concern (31cfm vs 51) ? My cpu's are dual L5630 and came with a passive heatsink.
 

Terry Kennedy

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If I have to order new fans I will, any suggestions will be welcome and I'll do my searching.
If other people have reported success with them, then it might be something specific to your system - bad fans or an improperly seated connector when you put them in the Supermicro hot-swap frames.
The other option is to just let the F8 fans run as is without bios control? Are they running full speed if the bios can't detect them? Because they are not loud. The airflow is a concern (31cfm vs 51) ? My cpu's are dual L5630 and came with a passive heatsink.
You don't know what the system will do with them because it doesn't think they're installed. It will probably just provide 12V to them and the fans will do whatever their default behavior is with the PWM lead disconnected.

Why don't you try one of the Arctic fans by plugging it directly into a motherboard fan connector? If that works, you most likely have a problem where the hot-swap fan frames plug into the chassis.
 

Defcon1

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I don't think the fan cage is the problem since it works just fine with the SM fans.

I believe my problem may be the fan itself. This is the fan I have - ARCTIC F8 PWM Fluid Dynamic Bearing Case Fan, 80mm PWM Speed Control, 31CFM at 22dBA - Newegg.com. Looks like this -



I think this is rev 1 of the fan, because the current version looks like this -


This only has a single pwm connector, the fans I was sold have 3 different connectors.

Can someone tell me if the rev1 is running at full speed if I only connect its 4pin connector into the hotswap cage? If not I'll buy new fans, which ones?
 
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Terry Kennedy

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That's probably the screwiest thing I've ever seen. It seems to have something to do with their "Patented PWM Sharing Technology", whatever the heck that is. The only thing I've seen that is close to that (and which actually worked) was on some ancient Intel boxed CPU fans, which shipped with a 4- to 3-pin adapter cable in case you were using the fan on an older motherboard.
Can someone tell me if the rev1 is running at full speed if I only connect its 4pin connector into the hotswap cage?
I doubt it is running at any predictable speed. And if it was, you wouldn't know because it doesn't show up in the Supermicro BIOS.
If not I'll buy new fans, which ones?
The ones that came in the chassis from Supermicro seem to be fine. A lot of people want to change fans to make the system "quieter" (and hotter). The manufacturers put a lot of effort into selecting the proper fans for the application. In the case (no pun intended) of Supermicro, they don't know what motherboard you're going to put in there - could be an Atom, could be some giant quad-processor beast. So it is probably overengineered a bit. Fixed-configuration system like Dell, Synology, Netgear, etc. will have tighter margins since the manufacturer knows the exact thermal output of the stuff in the case, as well as the maximum temperatures for the components, and design accordingly. I posted a longer version of this rant here a while ago.

On a more useful note, I would suggest only buying a fan where the manufacturer makes a detailed spec sheet available, so you know what you're actually getting.
 

Defcon1

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Terry, the reason I want to change fans is to reduce power draw and noise both. I agree the default SM fans are probably a good choice, but the fans that came with my case, 95L4 and 94L4, don't seem to have very high static pressure (0.8) so I'm hoping to find replacements that don't have adverse effects - airflow seems to be more important for the mid chassis fans since they need to cool the drive cages. The problem is finding fans with specs listed, like you said.

On another note, it took me a long time to get those damned F8's to fit into the SM cages (because of the huge plugs which I had to force into the holes) and now I have to do it all over again.
 

Terry Kennedy

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Terry, the reason I want to change fans is to reduce power draw and noise both.
I think the fans are a relatively tiny piece of the power consumption in the average SC836. I have a dual-E5620 motherboard w/ 96GB of RAM and half full of 7200 RPM 8TB He8 drives, and it runs around 250W input power. This is with 920SQ power supplies, which are not operating in their most efficient range (they'd like a higher load to be more efficient). The little bumps at midnight are a ZFS replication job that runs about 750MB/sec over 10GbE:

rz2_glaver_org-Watts-weekly.png

I agree the default SM fans are probably a good choice, but the fans that came with my case, 95L4 and 94L4, don't seem to have very high static pressure (0.8) so I'm hoping to find replacements that don't have adverse effects - airflow seems to be more important for the mid chassis fans since they need to cool the drive cages. The problem is finding fans with specs listed, like you said.
The best thing to do is to see what other people with the same chassis have done - if someone else has done the work already, that should get you going with the least amount of trouble.