CPU fan error

[Wombat]

This has happened once before, and a restart "fixed" it, but this morning it did it again.   I fired up the PC much earlier today, no probs, and when I shut it down in a hurry to go out, I didn't shut off the mains supply to the box like I usually do, so the power supply was still live.  I came back, and hit the power button on the PC, and got a CPU fan error message from the BOIS (its a UEFI thing). I hit the power button again to shut it off, opened it up and hit the power button again, and the CPU fan just twitched a bit but didn't start, so the same message appeared.  I wiggle wires, no change, and then pulled off the CPU fan connector and wiggled and replaced it, and then tried again and it went.

Motherboard is an ASUS Z87-A, and the CPU fan is the Intel issue standard one supplied with the i7 4770k processor.  To my mind, options are:

1. Hope that the contact cleaning caused by the removal of the fan connector has done it, and forget the issue.
2. Buy a new CPU cooler fan (other than the fancy heat pipe one I bought at the time, which didn't actually fit 'cos it hit the RAM modules)
3. Panic because my motherboard is on the way out.

What do the experts reckon?  (or even the "slightly more informed on such matters than me" folk reckon?)

[rusky]

I would suspect the fan first off.

If you have a spare system fan header you can test the CPU fan on that - like the ones either side of the 24 pin power connector.

[Biggsy]

Hard to know the cause from that, but anyway, having a stock cooler with an i7 K is like keeping a bird in a cage - rather cruel.  Get a bigger cooler and let it fly!

I doubt the motherboard is on the way out, though it is possible to blow fan headers (or what powers and controls them) by accidentally putting power *in* to them.  DAHIKT!  (I digress, obviously you haven't blown yours).

[Kim]

I would suspect the fan first off.

Indeed.  Give it a spin to see if the bearing's a bit rough.  Clean the fluff out.  Check the connector for obvious signs of dodginess.  Bung 12V up it and see what happens. 

Also check the BIOS configuration to see if it's running the fan at less than full power.  Most modern systems can do that, although they tend to come on at full speed for a couple of seconds at power-up to get them spinning.

[Wombat]

I'm inclined to take the lazy answer and just buy a new better fan, and then check it out afterwards.  It is indeed de-fluffed regularly (despite being a silent case with closely controlled air inlets, it does of course get the universal fluff in it)  The fans do indeed start up at full speed and then slow down, but it was only today I realised it was the CPU fan that was doing this, not the case fans, as I was watching it with the case side off at the time.

Its not gonna break the bank, and a not totally reliable CPU fan can get used for something else less critical.  I will indeed stuff 12v up its chuff, as long as we haven't already packed all the requisites for doing so, for the planned, and now suddenly in doubt house move.

[Canardly]

Replace the fan as above.

[Wombat]

I bought a Be Quiet! Pure Rock silent cooler, which is the version with a fairly massive ali finned heat sink and one fan, as opposed to the version which has a very massive ali heat sink and two fans.  Was a mild pain to fit, especially getting the fan onto the heat sink, as apart from anything else it has to suck through the heat sink, in order to agree with the general air flow direction through the case.  I can't put it on the other side of the heatsink as it'll hit the RAM modules.  I fired it up, and the fan ran immediately, but the BIOS squealed that there was a fan error and that I needed to enter setup.  I changed the fan profile to silent, and the fans revs are still only about 500rpm, but I'm assuming its meant to be that way, as its a 120mm fan running slowly, rather than a smaller one going flat out.  The fan control for it is claiming to be on 29-30%, and the CPU temp is around 30 deg C while I'm doing this, which is hardly hard work.   I did tell the BIOS setup to ignore CPU fan speed, as if temps went high, I'm pretty sure it would shut it down (like it did when the issue manifested itself a few days ago).  I immediately downloaded Open Hardware Monitor, which is what is currently telling me the temps and fan controller settings.  I'm assuming/hoping that the CPU fan controller is saying 29-30% because its sensing that's all it needs.  The other three case fans are on 60%, and its claiming fan controller 5 and 6 are on 100%, but it hasn't got a fan 5 or 6, unless you count the power supply fan, which is massive and I suspect fixed or controlled directly by the power supply.

I am currently assuming all is well...

[Kim]

That all sounds sane to me.  Controllers 5 and 6 may well refer to ports on the relevant chip that aren't connected to anything, and it wouldn't surprise me if there are some that can monitor fan speed but not control it.

Run something properly CPU intensive (perhaps a program designed to thrash all the cores for just this reason), and see how that affects things.

[Wombat]

Firing up Capture One Pro, (which has to suddenly render a hell of a lot of image previews), and immediately firing up a big 4K video, and also playing a youtube video resulted in a short rise to 50 deg C, which then pulled back down to 35 or so, and the CPU fan controller went to about 35%.  This all seems to make sense to me, and the relevant sphincter has unclenched somewhat now   

I'll keep an eye on it for a few days.

I thought it was quiet before, but its really quiet now.  As I hate noisy PCs, that's fine by me.