Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Motherboard fan question

New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?

TIA
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Default Motherboard fan question

On Sat, 12 Jun 2010 21:43:36 +0000, root ǝʇoɹʍ:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their processor.
These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying if
the tiny little fan fails?

No.

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Default Motherboard fan question

On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ǝʇoɹʍ:

On Sat, 12 Jun 2010 21:43:36 +0000, root ǝʇoɹʍ:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying if
the tiny little fan fails?

No.


I'll revise that and say that if said fan is monitored then there can be
an audible alert set up if the fan drops below a certain RPM. The fan
would need to have three wires to be monitored. Also in BIOS there should
be a setting to alert if the mainboard goes over a set temperature limit.
The default limits are usually good enough to use.

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Default Motherboard fan question

New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?


On most motherboards built today, there's a temperature sensor
associated with the CPU (sometimes several e.g. individual temperature-
sensing diodes in the CPU's cores) and others on the board. The
sensor values can be read out (often via SMBUS) by the BIOS or other
software.

Better motherboards use three-wire fans with tachometers, where the
tach frequency can be read out of the sensor chip.

Modern BIOSes will usually let you set a temperature alarm, on a
per-sensor basis, and arrange for some sort of emergency action if the
temperature rises too high or the fan speed drops too low. The
actions can involve slowing the CPU clock to reduce power consumption,
sounding an audible alarm, triggering an OS shutdown, or (in extreme
cases) just halting the processor(s).

Graphics cards could implement similar fail-safe mechanisms. I don't
know if they do.

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Default Motherboard fan question


"Meat Plow" wrote in message
news
On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:

On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying if
the tiny little fan fails?

No.


I'll revise that and say that if said fan is monitored then there can be
an audible alert set up if the fan drops below a certain RPM. The fan
would need to have three wires to be monitored. Also in BIOS there should
be a setting to alert if the mainboard goes over a set temperature limit.
The default limits are usually good enough to use.



Some motherboards have thermistors mounted under various chips and software
included on the setup disk with temp monitor and alarm.

I think my other PC has it, but its not obvious - I'd have to re-run the
setup disk to find out where it is.

Either that or I didn't bother with it last time I did a clean install.




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Default Motherboard fan question

"ian field" wrote in
news:bTTQn.27090$g76.4060@hurricane:


"Meat Plow" wrote in message
news
On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:

On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying
if the tiny little fan fails?

No.


I'll revise that and say that if said fan is monitored then there can
be an audible alert set up if the fan drops below a certain RPM. The
fan would need to have three wires to be monitored. Also in BIOS
there should be a setting to alert if the mainboard goes over a set
temperature limit. The default limits are usually good enough to use.



Some motherboards have thermistors mounted under various chips and
software included on the setup disk with temp monitor and alarm.

I think my other PC has it, but its not obvious - I'd have to re-run
the setup disk to find out where it is.

Either that or I didn't bother with it last time I did a clean
install.




often,before anything fries,you start seeing wierd
things,glitches,freezes,etc.

maybe you could/should build a temp monitoring system,separate from the PC
circuitry,with red LED's that flash when a zone goes overtemp,and voices
"warning,warning" in a robotic voice ala Lost in Space.(use a speech chip
from a greeting card...)
it could even kick in an emergency backup fan,and perhaps even a freeze
spray blast to chill things down.

[end "humor" mode]

--
Jim Yanik
jyanik
at
localnet
dot com
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Default Motherboard fan question

On Sat, 12 Jun 2010 15:25:58 -0700, Dave Platt wrote:
New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?


On most motherboards built today, there's a temperature sensor
associated with the CPU (sometimes several e.g. individual temperature-
sensing diodes in the CPU's cores) and others on the board. The
sensor values can be read out (often via SMBUS) by the BIOS or other
software.


Better motherboards use three-wire fans with tachometers, where the
tach frequency can be read out of the sensor chip.


I've yet to see a motherboard that did anything with the chipset fan
speed data. You can run an application that'll monitor it, but almost
nobody goes to the bother as most such applications, written for
microsoft windows, were modeled to resemble someting out of a comic
book and are an eyesore even when minimized. Linux' lmsensors doesn't
require such an eyesore on the desktop, but is a bit of a PITA to set
up.

The better motherboards either use a quality fan or a heatpipe to a
heatsink cooled by the cpu fan.
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Default Motherboard fan question

On Sat, 12 Jun 2010 18:08:50 -0500, Jim Yanik ǝʇoɹʍ:

"ian field" wrote in
news:bTTQn.27090$g76.4060@hurricane:


"Meat Plow" wrote in message
news
On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:

On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying
if the tiny little fan fails?

No.

I'll revise that and say that if said fan is monitored then there can
be an audible alert set up if the fan drops below a certain RPM. The
fan would need to have three wires to be monitored. Also in BIOS there
should be a setting to alert if the mainboard goes over a set
temperature limit. The default limits are usually good enough to use.



Some motherboards have thermistors mounted under various chips and
software included on the setup disk with temp monitor and alarm.

I think my other PC has it, but its not obvious - I'd have to re-run
the setup disk to find out where it is.

Either that or I didn't bother with it last time I did a clean install.




often,before anything fries,you start seeing wierd
things,glitches,freezes,etc.

maybe you could/should build a temp monitoring system,separate from the
PC circuitry,with red LED's that flash when a zone goes overtemp,and
voices "warning,warning" in a robotic voice ala Lost in Space.(use a
speech chip from a greeting card...)
it could even kick in an emergency backup fan,and perhaps even a freeze
spray blast to chill things down.

[end "humor" mode]


Ummm not to spoil your humor however, there is/was a PCI card and front
panel that did just that. Designed for those who used to overclock their
systems and run them on the ragged edge.
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Default Motherboard fan question

On Sat, 12 Jun 2010 18:20:19 -0500, AZ Nomad ǝʇoɹʍ:

On Sat, 12 Jun 2010 15:25:58 -0700, Dave Platt
wrote:
New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying if
the tiny little fan fails?


On most motherboards built today, there's a temperature sensor
associated with the CPU (sometimes several e.g. individual temperature-
sensing diodes in the CPU's cores) and others on the board. The sensor
values can be read out (often via SMBUS) by the BIOS or other software.


Better motherboards use three-wire fans with tachometers, where the tach
frequency can be read out of the sensor chip.


I've yet to see a motherboard that did anything with the chipset fan
speed data. You can run an application that'll monitor it, but almost
nobody goes to the bother as most such applications, written for
microsoft windows, were modeled to resemble someting out of a comic book
and are an eyesore even when minimized. Linux' lmsensors doesn't
require such an eyesore on the desktop, but is a bit of a PITA to set
up.

The better motherboards either use a quality fan or a heatpipe to a
heatsink cooled by the cpu fan.


For the most part decent mainboard provide enough surface area to their
Northbridge chipset and onboard video to be passively cooled. The extreme
end boards offer heatpipes and fancy servo fans.
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Default Motherboard fan question

On 13/06/2010 7:43 AM, root wrote:
New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?

TIA


I have a fanless NVIDIA based graphics card that I was running with
inadequate ventilation. When used on graphics intensive tasks, it
started behaving as if there was increasing fog in the scene being
viewed. This would have reduced the amount of processing it needed to
do. The GPU didn't fail, and this effect was apparently invisible to the
software driving it. I infer that it was a designed response to excess
temperature.

A fan cooled version with a failing fan would presumably do the same thing.

Sylvia.


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Default Motherboard fan question

On Sat, 12 Jun 2010 22:17:21 +0000 (UTC), Meat Plow
wrote:

On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:

On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying if
the tiny little fan fails?

No.


I'll revise that and say that if said fan is monitored then there can be
an audible alert set up if the fan drops below a certain RPM. The fan
would need to have three wires to be monitored.


Not necessarily true. THe chipset could easily have an
over-temperature detection circuit built into the die. At least that's
how I'd do it, since that would detect multiple problems that
monitoring just the fan's rotation would not do. After all, a fan
turning is not always a fan delivering power!

Also in BIOS there should
be a setting to alert if the mainboard goes over a set temperature limit.
The default limits are usually good enough to use.


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Default Motherboard fan question

On Sun, 13 Jun 2010 08:35:38 -0400, PeterD ǝʇoɹʍ:

On Sat, 12 Jun 2010 22:17:21 +0000 (UTC), Meat Plow
wrote:

On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:

On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:

New motherboards often have a small fan covering one of the bridge
chips. Likewise, expensive graphics cards have a fan on their
processor. These fans are cheaply made.

Is there protection for the MB/card to keep their chips from frying
if the tiny little fan fails?

No.


I'll revise that and say that if said fan is monitored then there can be
an audible alert set up if the fan drops below a certain RPM. The fan
would need to have three wires to be monitored.


Not necessarily true. THe chipset could easily have an over-temperature
detection circuit built into the die. At least that's how I'd do it,


snip

No of course it's not necessarily true. I can't speak for every frigging
manufacturer out there. Certainly both cases are true, MB temperature
monitors and monitored fans and both. My MSI MB has a monitored rear
120mm fan and MB temperature monitoring. Most of the boards I've dealt
with are Intel, Asus, and MSI. I can only recall one using a small fan on
the pci bridge chip. The rest were equipped with a large heat sink. The
emphasis on using one large fan in the rear to quietly exhaust inside air
rather than having a bunch of small 5000 rpm fans making a racket.
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Default Motherboard fan question

On Sat, 12 Jun 2010 21:43:36 +0000 (UTC), root
wrote:

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?


Some do, most don't. Most machines require running applications
software to monitor the cpu, mb, hd, fan speed, etc, which then
initiates a shutdown. This is typical:
http://www.hmonitor.com
Other motherboards (some Dell's) have the monitor built into the BIOS.
Most CPU's will protect themselves from overheating by slowing down
the clock. Motherboards with this feature usually allow setting the
overtemp alarm threshold. This is common in server BIOS's. If you
see a "thermal event shutdown" in the BIOS log file, the computer was
turned off automagically due to overheating or fan failure.

Intel provides various monitoring utilities:
http://www.intel.com/support/motherboards/desktop/sb/cs-012552.htm

You're correct to worry about the survivability of the little fans.
Once they overheat, they melt. When they melt, they slow down or
stop. You might have some luck tearing the fan apart and applying
some oil, but that only lasts for a few weeks. Replacement is the
only real option. If you want to keep your unspecified model
motherboard fan alive, keep the dust and crud out. Breaking it loose
with a paint brush, and blowing the case clean with an air compressor
is my method.


--
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http://www.LearnByDestroying.com
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Skype: JeffLiebermann AE6KS 831-336-2558
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Default Motherboard fan question

root wrote:
New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?

TIA


There is a cheap "Fan Alarm System" card available:
http://www.outletpc.com/c1685.html
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