Fan stopping by itself...?!?!

toNka · Post by **toNka** » Sat Mar 03, 2007 1:54 am

Okay, maybe someone has had this happen to them as well.
I have some Nexus 120mm fans, you know, the ones that look like they are made of Velveeta.
So I have one as an exhaust and one mounted at the front of my Ninja.
I run them both through my Zalman FanMate.
I don't put them on the knobs but on the switches.
These have 3 settings: Off, 5v, 12V.
I typically run them at 5v.
Some times I notice my CPU temps idling higher than normal.
I look inside my case and the fan has stopped!
I switch it to Off then back to 5v, no luck.
I try 12v, then it goes.
I can put it back to 5v then and it will run for a while then stop eventually.
Sometimes I can even get it to start at 5v, but it will eventually stop.
I have never had a problem with these fans running at 5v in the past.
They always start and never stop... until now.
You think my controller is crapping out, could it just be the fan?
Why would the fan stall?
What say you SPCR?!?!

toNka · Post by **toNka** » Sat Mar 03, 2007 1:57 am

Oh, BTW, it's not a major threat.
The CPU runs fine fanless, just idles in the mid to upper 40s.
I prefer to have it where it belongs, low 30s.
But if I start doing something intensive it will hit 60+!
That's what scares me.

wwenze · Post by **wwenze** » Sat Mar 03, 2007 3:16 am

Tthe FanMate is just a resistor so it cannot control exactly the voltage "fed" to the fan.
The Nexus draws so little power that the effect of FanMate reducing voltage is greater than what it is supposed to be - i.e. the Nexus is getting less than 5V

That, plus the wearing-out of the bearings, dust in the mechanism, causes the fan to only stop now.

BrianE · Post by **BrianE** » Sat Mar 03, 2007 9:47 am

Sorry this doesn't help with your question, but what Fanmate is this exactly? I don't recall ever seeing a version with a switch like that and the ones I have (Fanmate 2) only have a variable control knob.

I am wondering now if you are running them through the Fanmate and also through a simple 5V/12V switch (in series). If that's the case, then you are probably actually running your fans at 4V or less because the Fanmate limits maximum output to ~11V. (BTW, the Fanmate is NOT just a resistor - it is a voltage controller.)

I have no idea why they would stop running after a while, but I would look at heat/resistance related problems. Maybe the Fanmate is dusty and drops the voltage even more as it heats up?

toNka · Post by **toNka** » Sat Mar 03, 2007 10:23 am

I said FanMate but now I realize that is wrong.
FanMates are those little black boxes they give you with a lot of their coolers.
I have the Zalman ZM-MFC1.
http://www.zalman.co.kr/eng/product/vie ... 1&code=017

Tzupy · Post by **Tzupy** » Sun Mar 04, 2007 9:42 am

From my experience the 120 mm Nexus doesn't start at 5V, and SPCR found the same issue:
http://www.silentpcreview.com/article69 ... html#nexus
You could run them at 6V, I find it hard to believe that you need 500 rpm for silence, 600 rpm would be nice too.