case fans not starting automaticly

Lauw · Sep 10, 2015

Hiya

Been having an issue with the case fans lately...
I`m using windows 10 since a month and the case fans were spinning just fine.
But now since i replaced my faulty power supply with a new one the intake on the back in my case it`s case (lol) stopped starting automaticly. the exhaust did start automaticly.

i disconnected the molex connectors and reconnected them and now the exhaust stopped spinning automaticly too.

I have to push them a little to get them running basicly.

not sure why this is happening.
Not something you`d expect when having a new power supply.

A little help to figure out in wich direction i should be searching would be great.

I`ve had this problem before when i was using windows 7 pro. I did a reinstall and that fixed it for some reason. though there has to be an other way. these fans are wicked.

greats

elneelo · Sep 10, 2015

Have you considered using a fan controller?

Lauw · Sep 10, 2015

yes i did, though it should be working without it too just fine.

elneelo · Sep 10, 2015

Lauw :

It should, and I am not sure why they wouldn't be :/ Can you connect them directly to the motherboard without the need for molex?

Lauw · Sep 10, 2015

not that i know, these fans had molex conectors from the beginning and i dont see any 3 pin connectors on the motherboard besides those of the north and south bridge.

Paperdoc · Sep 10, 2015

First question to check: are you using any resistors in the fans' power connections? Sometimes these are sold as "low noise adapters" because they are used to reduce the voltage to a fan, thus reducing its speed and noise.

Now, if you are NOT using those, then the fans both ought to be receiving the full 12 VDC power supply at all times, and should ALWAYS be running at full speed when the computer is on. Your post says lately they do not even start up, BUT you can get them to start if you push them. You imply that, once they start, they keep running.

Those are symptoms of fans with worn bearings that are likely to stop working permanently very soon. I bet if you shut down and give each fan's blades a quick push with your finger, they will NOT keep spinning for a few seconds and slow down. They will stop almost immediately. If you push them with your finger slowly, they probably feel "stiff" and not easy to push. The solution is to replace those fans very soon before you lose all their cooling power. This has NOTHING to do with the power supply replacement. It just happens those fans finally have reached a late stage of wearing out.

Lauw · Sep 11, 2015

thanks for the thorough explanation, I`ll get them replaced very soon.

and i`ve never heard of low noise adapters.
don`t see the point of it since Fans these days run very quite on there own if you pick the right one.
and yes thats exactly what i`m stating.
Edit: though they only need a push, from that point they get themselfs to there set speed.

I`ve had a few other people who tried to talk me in buying a fancontroller. this is the second time i`ve created a post like this btw.
even though it might have worked for a while, your explanation is to the point, so a few big thumps up.

greats and a big thank u.

Edit: my fans came standard with the case and are connected to 2 speed switches. not sure if i should reuse the switches or if this is even possible? Any experience with this?

Paperdoc · Sep 11, 2015

VERY likely the "2 speed switches" allow you to set each fan to full speed or a slower speed. This latter is exactly like using a "low-noise adapter" resistor. You cab bypass the switches entirely, or just leave them on high speed.

Thanks for Best Solution.

Lauw · Sep 12, 2015

well i just set them at medium speed. they make a little buzzing noise now. they are pretty old, like 7 years. They are already shapeshifting into some kind of prehistoric creature. (never seen this before) lol

itll have to do for now.
cant afford a new motherboard, perhaps the problem will go away if i leave them running in medium for a while.

Edit: just found out there are 2 4 pin fan connectors on my motherboard. I bet i can bypass the fanspeed switches with another set of 4 pin fans (without molex)
will my motherboard adjust speed by itself when needed or will i have to buy a fan controller anyway?

No problem by the way.

greats And thanks again

Lauw · Oct 4, 2015

Hi again,
I`m not sure its related but there's a big chance it is. perhaps someone with more experience could get rid of the doubt.

since a week or so ive been having a rattling noise at start up.
please tell me if i`m thinking in the right direction.
Is this also a sign which is referring to the worn bearings??
also I`m having a problem with one of my HDD which are in a raid 0.
i`m using system care pro 9 beta 2.0 and its been telling me quite some time there are errors being found. Only 1 at a time though.
In the beginning there was only " HDD has no access to read only mode".Not that big of an issue i think.
Though recently another error occurred: "the volume bitmap is incorrect"
not sure what it means but could these errors also be a clue to the rattling noise at start up?

thanks

Paperdoc · Oct 4, 2015

Sorry, I missed your post from Sept 12. If you buy and install standard 4-pin (NOT 3-pin) case ventilation fans and plug them into the mobo 4-pin fan ports, your mobo can automatically control those fans for you. You will not need any separate fan controller, and you will not use the old fan speed switches. The default setting in BIOS Setup for such ports is to do automatic control. But there are other options there, too. So IF your new fans appear not to be under control (and hence running slower at low processing loads), check that the BIOS setting for the port is correct.

Important detail: you say the mobo has two 4-pin fan connectors But look closely at the labels on each one. The mobo port labelled CPU_FAN must ONLY be used for the CPU cooler. IF you have a fan port labeled PWR_FAN you can connect a fan to that but it will only run full speed. (This type of port, missing on many mobos, is not intended for case fans and exercises no control.) The proper ports for use with case ventilation fans will have a label of either SYS_FAN or CHA_FAN. If you have two of those, each can be used to connect one fan.

IF you have only one port for a case fan, you can usually connect two fans to that one port by using a 4-pin fan splitter. Most mobo ports can supply up to 2 "normal" case fans, but not more.

Now, on to today. The "rattling sound" could easily be worn fan bearings. Typically worn bearings at some point in their deterioration path start up from cold by making noise, then quiet down and maybe go silent as they warm up in a few minutes. Running the fan warms the bearing components enough to tighten up the clearance in the bearing, making it stop rattling around.

The problems you describe with your RAID0 array are MUCH more troubling. They do appear to indicate the beginnings of failure of at least one of the HDD units involved. The problem is this: a RAID0 system only works if BOTH drives are good. A failure of ONE of the drives means you can get NOTHING from the array! So, since you have warnings of failure (maybe soon!) NOW is the time to be sure you have ALL the stuff on that array backed up. Then decide when you can buy a new drive (or two, IF you plan to continue by re-establishing a new RAID0 array with two new drives) and moving all your stuff to the new drive(s) BEFORE the array does fail.

Lauw · Oct 5, 2015

yes noticed there were two SYS_FAN headers with 4pins. Since i`m also considering of putting 2 in the Front I should indeed get those splitters you mentioned.
I didn`t even knew these existed so thanks for bringing that up.

okay, well considering i used one new and one old HDD, the new one has only been used for this raid and nothing else, i probably should get rid of the old one. I`m aware that i`ll have to reinstall everything including the OS.

I believe it would be a waste of money to get 1 HDD to be able to establish a raid config. again. The best option is surely backing everything up just to be safe and when the time comes, ill be getting myself an SSD. Hopefully i can get through fall with this setup. By then "the money for GB" rate for SSD`s is probably gonna be more desirable.

Lauw · Jul 11, 2016

Hi again, I swapped my old system with a newer one and made my old system ready for sale. So I replaced the fans with new ones but still they are not spinning up automatically. this time i connected the 3pin fan plugs to the 4 pin headers. so no speed switches are involved. also cut of the original fans.

Is there something i`m overlooking?

greats.

Paperdoc · Jul 11, 2016

So you have new fans only - not any old ones - and they are connected to where? To mobo SYS_FAN headers? Well, check in BIOS Setup how those headers are configured. I don't see any specification above about what maker and model number of mobo you have. But I have realized recently that many mobos are placing 4-pin headers on the mobo but making them work only as 3-pin headers in Voltage Control Mode of DC Mode, and not in PWM Mode. IF you mobo is doing that and you are using 3-pin fans, you need to verify that the headers are configured to Automatic or Normal mode, so that it does make the fan speed change according to the heat load and temperature. If they are set to a fixed speed or to "Quiet Mode" or something, or to "Ignore", the fans may not be getting enough voltage to start up. By the way, have you tried pushing each fan lightly with your finger? Does it spin freely or is it stiff?

Lauw · Jul 15, 2016

the motherboard im talking about is a gigabyte EP35-DS4.
I dont know about the bios options, ill check this in the next couple of days. the fans run freely or similar to the original ones after pushing them. And yes new fans only, connected to SYS_FAN headers indeed.

Paperdoc · Jul 15, 2016

The manual says the mobo has four fan headers. One is for the CPU_FAN and certainly is 4-pin. In the manual on p. 50 it says you can set its operation to either Voltage Control Mode for a 3-pin fan, or PWM Mode for a 4-pin fan.

One header is called PWR_FAN and has 3 pins. It is NOT used for any fan and it cannot control any fan's speed.

One header labeled SYS_FAN1 is for a case ventilation fans and has 3 pins. The labels of it on p. 25 if the manual indicate that it also cannot control a fan's speed, although that is unusual.

The fourth header, labeled SYS_FAN2, has 4 pins and its labels indicate that it can control a fan's speed. However, the labels appear to indicate that is is really one of those Voltage Control Mode headers that do NOT provide a PWM signal on Pin #4, and simply act like a 3-pin fan header. In that case, it can control either 3-pin or 4-pin fans, and even do that for two fans connected to it by a Y-splitter. It may not be able to control the speeds of true 4-pin fans if you use an actual 4-pin Hub, and not just a Splitter. So, try using a Y-splitter with your two fans, plugged into the SYS_FAN2 header. Then verify its settings in BIOS Setup.

Lauw · Jul 27, 2016

okay well i guess ill have to leave it like this then since my fans only have 3 pin.
also not gonna bother with buying a new set of fans or a fanhub.

So if i just add the 2 3 pin fans to a 4 pin y-splitter and connect it to the SYS_FAN2 header they should be both spinning up?

Paperdoc · Jul 27, 2016

Yes, that's the right way to do it. That should get you both fans under automatic control by the mobo.

Lauw · Jul 29, 2016

Paperdoc :

Okay thanks, easy and cheap fix.

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