IC7-MAX3 - fan RPM's cause shutdown

Hi!

I have a IC7-MAX3 with an Thermaltake Spark 7. When running at full speed
(6000rpm), the motherboard fails to read the rpm's. It seems that the max
rpm for MB is around 5500. When above 5500, the MB thinks that fan is
failing and initiating a shutdown.

Anybody else seen this??

SpeedyGonzales

 

could be the fan itself giving bad RPM reading above a certain speed as well
as the board...

--

Thomas Geery
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The pulse from the fan tacho is likely to be poorly shaped or
low-amplitude or both. Some 3rd-party heat-sink vendors use
unknown-pedigree fans. Pulse-integrity can be checked using a
correctly-compensated low-capacitance probe on an
oscilloscope.

Anyway, 6000RPM must sound like a jet airliner.............
Doesn't the Thermaltake come with a manual control
that can be put in series to reduce the maximum speed ?

John Lewis

 

Don't connect the fan to the mb then. Connect it to the PSU directly
and disable cpu fan monitoring in the bios. That's what I did on my
IC7.

 

There is an manual option on the fan, but that's not the point.

The point is: The mobo can't read rpm's above aprox. 5500 rpm's!

I am running in thermal/auto mode which gives me an initial 2000 rpm's at
42C and at 55-56C it's around 3300rpm's.
It works for me, and fan noise is okey!!

SpeedyGonzales

 

the "point" is that it might not be the mobo! it could be the FAN!

--

Thomas Geery
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Bullshit. The motherboard can correctly read the speed of whatever fan you
use, provided it outputs a decent tacho pulse. As John said, the problem
here is with the particular fan you are using, not a problem with the
motherboard or the system monitor chip.

If you don't want the system shutting down, disable the "shut down on CPU
fan fail" option in the BIOS.
--


Richard Hopkins
Cardiff, Wales, United Kingdom
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I wonder if you are talking from experience, or are just a "clever guy" ??
(Since I am bullshitting)

Do you have a IC7-MAX3 with a fan speedy above 5500??
(Don't need answers from users who don't have high fan speed)

SpeedyGonzales

 

I have an IC7-G with a high speed fan on it. reads fine. why would you be
so absolutely sure it cannot be the fan? have you tried a different fan?

--

Thomas Geery
Network+ certified

ftp://geerynet.d2g.com
ftp://68.98.180.8 Abit Mirror <----- Cable modem IP
This IP is dynamic so it *could* change!...
over 118,000 FTP users served!
^^^^^^^

 

I am not sure that it's the fan....but I need answer from users like you who
have a high rpm cpu fan, so I can eliminate that the MOBO is not capable of
reading high rpm's.

Speedy

 

It is very easy to check the fan tacho with the appropriate equipment
-- see my original reply.

Reading the opinions of a hundred people will still not confirm
the problem-source in your specific case. Only the requisite
electrical measurements on YOUR fan.

John Lewis

 

Richard is a clever guy, and he's right on this one.

This has been a problem ever since Abit launched the shutdown on fan failure
"feature" on the old KT7A. Some fans have a different electrical signature
and the bios has trouble reading it. As a result, a misidentification can
shut down the PC even when the fan is working properly.

Most people who have that problem, and many who don't, disable that feature
in the bios.
Still another possibility is explained in your owner's manual. The hardware
monitoring features occupy I/O addresses from 294H to 297H. If you have a
NIC, sound card, etc, using an address in that range you could get bad
readings.

I'm writing this on an IC7 with a Vantec Aeroflow running at 5700+ rpm.
Neither the bios, Hardware Doctor or Motherboard Monitor have any problem
reading fan speed accurately.

This quote is from the help file for MBM5, but it make provide a clue as to
why not all fans are created equal:

Fan Type
Some Fans will show a too high RPM or a to low RPM as the pulses they send
per second don't match what the sensor chip expects.

There are 11 settings, /1 to /10 which divide the readings by that amount
and *2 which muliplies the reading by 2. Default setting for 99% of all
boards will be /1

Fan Dividor

Default this value is 4, this means that fans as low as 1300 rpm will show
up, the lower you set this value the more accurate the fan RPM will be, but
if you set it to low your fan might not show up. Not all sensor chip support
values higher then 8, if yours does not then selecting 16, 32, 64, or 128
will simply make mbm use the 8

 

If I wasn't, I wouldn't have replied.

Yes. Reads over 7000rpm without any problems, or drop-outs at all.
--


Richard Hopkins
Cardiff, Wales, United Kingdom
(replace .nospam with .com in reply address)

The UK's leading technology reseller www.dabs.com
Out with the old & in with the new at www.dabsxchange.com
Get the most out of your digital photos www.dabsxpose.com

 

IC7-G, chipset fan running at 6750 rpm according to ABIT EQ, no problems.