Major hardware problems - fans shutting down - overheating

[loreleibansidhe]

Hi.
i've got a major problem with my computer. It has three fans, and
whenever i switch the computer on, only a maximum of two of them work
at a time - it's completely random which ones decide to work at which
time.
i've tried cleaning the fans, so it's not that.
Apparently there's no problems with the PSU, either.
Does anyone know what this could be?

Also, it says the system temperature is much higher than it actually
is, so it shuts down when it thinks it's
overheating.
Could this be a virus?
Or is it a hardware problem?

Someone please help; i can only safely have the computer on for about
20 minutes at a time right now.

 

[SteveH]

Hi.
i've got a major problem with my computer. It has three fans, and
whenever i switch the computer on, only a maximum of two of them work
at a time - it's completely random which ones decide to work at which
time.
i've tried cleaning the fans, so it's not that.
Apparently there's no problems with the PSU, either.
Does anyone know what this could be?

Also, it says the system temperature is much higher than it actually
is, so it shuts down when it thinks it's
overheating.
Could this be a virus?
Or is it a hardware problem?

Someone please help; i can only safely have the computer on for about
20 minutes at a time right now.

You say the PSU is ok, but it could be short on power, this could be why the
fans don't all start. Try disconnecting non-essential stuff and see what
happens.
Also, how do you know the system temperature isn't high, how have you
measured it? It could be shutting down because the CPU is overheating.
Lastly, it will be easier to help if we know what is in your PC, so can you
list the spec please.

SteveH

 

[BigJim]

I had problems with an ECS board with the cpu fan. It was the motherboard,
so I got an adapter and connected it directly to the PS. You wrote that it
is not the PS but I would check it again.

 

[Paul]

Hi.
i've got a major problem with my computer. It has three fans, and
whenever i switch the computer on, only a maximum of two of them work
at a time - it's completely random which ones decide to work at which
time.
i've tried cleaning the fans, so it's not that.
Apparently there's no problems with the PSU, either.
Does anyone know what this could be?

Also, it says the system temperature is much higher than it actually
is, so it shuts down when it thinks it's
overheating.
Could this be a virus?
Or is it a hardware problem?

Someone please help; i can only safely have the computer on for about
20 minutes at a time right now.

Find adapters to connect the fans directly to the power supply.
That will bypass whatever problem the fan headers on your
motherboard are having. Some motherboard fan headers have
PWM or linear speed controls, and damage to the circuit feeding
the header might cause the fan to stop. Or it could be some piece
of software on the machine, that is commanding the state of the
fans.

Modern processors do contain internal thermal protection, and
that is supposed to be tied to the power supply PS_ON# signal.
In the event that a recent Intel processor reaches perhaps
85C tp 90C or so, that could cause the entire computer to
switch off, fans and all. The calibrated trip point is set
inside the processor. If you experience power off events
like that, then you need to investigate why the CPU is
not being cooled well enough. If the CPU fan is stopping,
that is enough to do it. (If you move the CPU fan cable to
an adapter, that may be enough to maintain your CPU cooling.)

This is an example of a fan adapter:

http://www.bigfootcomputers.com/Mer...=PROD&Product_Code=2904CGWA&Category_Code=120

The fan adapter pictured is not ideal. A better one has two
Molex four pin connectors, allowing multiple adapters to
be connected head-to-tail.

The three pin connector with the single yellow wire on it, goes
to the motherboard header. The yellow wire is there, so that
the fan RPMs can continue to be monitored, if the motherboard
and software support monitoring. The second three pin connector
goes to the fan, and carries the red and black wire with the
+12V and GND from the Molex disk drive connector. If the adapter
has two four pin Molex connectors, one male and one female, then
you can connect more than one adapter to the same disk drive
power cable from the power supply.

This probably is not a power supply problem. If the +12V was
flaky, your motherboard would have crashed by now.

HTH,
Paul

 

[Conor]

Hi.
i've got a major problem with my computer. It has three fans, and
whenever i switch the computer on, only a maximum of two of them work
at a time - it's completely random which ones decide to work at which
time.
i've tried cleaning the fans, so it's not that.
Apparently there's no problems with the PSU, either.
Does anyone know what this could be?

Yeah...your PSU is too low rated.