Fans Spin Stop and Spin Up Again

• #2

Update - Solution inconclusive pending further testing.
Bootup
Del, del, del, etc,
Hello bios.
Mouse pointer won't move.
I unplugged all nonessential ( for the sake of bios) USB devices, (foot pedals, XKeys, game pad, etc).
Mouse back to normal, the Logitech G600 leds came on, and pointer moves as it should, all good.
Then I plugged all USB devices back in.
Mouse pointer continues to move normally.

Edit, Update Repeated exact test above, mouse pointer won't move at all. 2nd Test Failed.
Edit, again, Unplugged all non-essential USB devices, then rebooted into bios, Success.
Next, I rebooted into bios with each non-essential USB device by itself, mouse normal.
Planning to do reverse testing by process of elimination, I rebooted again with all non-essential USB devices plugged in, and mouse worked normally.
The solution remains inconclusive, and/or the cause is intermittant, so I'll have to defer to you guys for more expert opinions.
Thanks for indulging all this.
Cheers.

Last edited: Sep 20, 2020

• #3

Too much power draw on any one port or hub?
That will shut a port down without warning.
Its the only thing I can think of.
You might adjust your topology to better balance power distribution if thats what it is.

• #5

My electrician friends would say something like "lock rotor current" in regard to a motor
that is trying to start-up. This refers to the high-current needed to start up a motor.

For this reason, I wouldn't recommended running variable voltage fans at a voltage
which is too low for them to spin. You want them spinning some at all times.

Straws. Again.

• #7

Ok, I get in trouble for my opinions, but I am a hw sw engineer and I make things
and have experiences beyond the norm. 4 case fans is just crazy. let me explain.

The last project I worked on was a MPPT solar charge controller. It involves MOSFETs.
I have some very nice 500W+ power mosfets in synchronous rectification, which isn't easy.
Each mosfet has a meager heatsink of 2 x 4 x 1/2 inch, finned. My prototypes operate
in an outbuilding which has poor airflow. When the weather is on the cold side, there is no
need for a fan, but in the summer I discovered that yeah a fan is needed. So I added some
control circuitry and programmed the controller to turn the fan on and off as needed.
In a still-air outbuilding exposed to the sun, it can get 100 to 110 deg F inside on a hot day.
A single case fan of the large variety running at the usual 1200 RPM or so is plenty
to get the air moving and thermal sensors measure about 160 deg F maximum with
a 20 to 25 amp current flow, or about 250 to 300 watts.

One other observation is that FANs are like speakers in a hifi set-up.
Proper positioning and sensible flow rates and directions are important or the fans
will quite literally interfere with each other and result in less airflow.

Ok, sorry for the lecture, but all that is really needed is to convert a still-air environment
into a moving-air one. A gentle steady breeze.

Now as to your problem there are too many variables and not enough
to know why the fans just suddenly quit running. How were they connected?

• #11

I would have probably included PTC fuses on the supply that powers the mb controlled fan circuitry,
you know just in case a fan tries to draw too much power (but NOT on the CPU fan). This is a self-resetting
fuse that resets itself when power is removed. (Which I assume you have powered off at some point.)

If there is no protection, then ?? overload? Hard to say if you've got a PTC that won't reset,
or a burned mosfet somewhere, or just a bios bug. Something stopped passing power.

I suppose I would whip out a DMM and check the fan headers for voltage. Hey theres an idea.

hilliardpudge1969.blogspot.com

Source: https://forum-en.msi.com/index.php?threads/z490-fan-mouse-issues.345786/

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