Fan beeps

My computer boots up ok but after minutes, or even hours sometimes, of
running, the box starts to beep and a light flashes red/green on the front
of the case. The light that flashes is labeled 'fan fan'. Does anyone here
have a clue as to what it is that I need to look at. There has got to be 6
or so fans in this computer. I have removed and cleaned all of them. When
this problem first started, there was a forest of dust buildup inside
especially around the cpu fans.

jnwayn wrote:
> My computer boots up ok but after minutes, or even hours sometimes, of
> running, the box starts to beep and a light flashes red/green on the front
> of the case. The light that flashes is labeled 'fan fan'. Does anyone here
> have a clue as to what it is that I need to look at. There has got to be 6
> or so fans in this computer. I have removed and cleaned all of them. When
> this problem first started, there was a forest of dust buildup inside
> especially around the cpu fans.
>

Maybe the label reads "fan fail" ?

Is this a prebuilt computer ? What make and model ?

If it was home built, then maybe this fan thing is a separate
subsystem or something. You'd have to shed some light on what
is inside the box, to get more help. (Means taking the side
off, and figuring out what is stuffed in the box.) Observing
what the fans are wired to, is going to help you understand
what is monitoring the fans.

Motherboards sometimes use a SuperI/O chip that has a hardware
monitor section, to keep track of fans. There can be three to
five channels of fan monitoring. Each channel accepts as input,
an RPM signal from the fan. The signal pulses twice per
revolution. The signal is only available on three or four
wire fans. Many case fans have only two wires, so no monitoring
of those is normally possible. (The two wires carry +12V and GND,
and two wires is just enough to power the fan and make it spin.
RPM would be a third wire. PWM, or speed control, can be a
fourth wire. Cheap fans have only the two wires.)

Some server motherboards, can have more than one chip, and hence
additional monitoring features.

Once the ability to monitor RPMs is present, then it is up to
some BIOS or software feature, to decide how slow is too slow.

A more obscure feature, is a fan that has a locked rotor signal.
Such a feature may make it marginally easier to report fan
problems, as then no software is involved (that might make it
easier to drive a fan fail light). But LR fans aren't typically
used on computers.

Paul

Have I missed something? Could you give me the exact configuration you
are using?

Board:
Board revision:
Bios:
Operating system:
Memory (Exact Type, Chip-Nr., how many DIMMs and where they are
inserted):
PCI card(s): (exact)
Hard Disks:
Raid Level or SATA:
CD-ROM drive:
Power Supply:

Rodger