System Noise - pulsing whir
in [Linux Hardware]
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From: Kevin the Drummer on 3 Jun 2010 11:39 I'm having trouble with noise in my system. I custom built the system doing all the usual things to make it quiet, and it was running just great. It was quiet enough that sitting with my head 1m away from the system the florescent lights 2m away were louder by far than the computer. Then my ABIT-AV8-3rd-Eye motherboard died and I had to replace it with a Tyan Tomcat K8E S2865G2NR motherboard. After doing that the machine made a "whir whir whir ..." sound, with the whirring being about one second between whirs. I thought I might have damaged something in the swap, and I thought the new noise was coming from the CPU fan. Last night I replaced the old Zalman CNPS7700-AlCu CPU cooler with a similar Zalman CNPS 7500 AlCu LED CPU cooler. But, when I powered on the unit I get the same whir. I didn't really want the LED in the CPU fan, but it turns out that it's giving me a hint as the brightness of the LED in the CPU fan is pulsing exactly in time with whirring noise. I wondered if I might be able to get at some fan controls via the BIOS, and booted into that screen. I found another clue, the whirring is exactly in time with the system clock, whirring just as each second on the clock ticks by. I put an add-on fan speed control in-line with my CPU fan power. When I turn the speed control up and down it works as expected, and the normal fan noise changes with fan speed. But, the whirring noise stays constant with CPU fan speed. The hard drives seem quiet enough, and not the source of whirring. The case fans are quiet enough that I have to strain to hear them with my ear right by them. My video card is fan-less. My power supply isn't making the whirring sounds. What am I dealing with here? Do I have a motherboard that causes this? Are the Zalman fans that I love in all my other systems being upset by the Tyan motherboard? What else can I do to troubleshoot this? My next random attempt, half in panic, would be to swap motherboards again. Thanks all..... Maybe I should embrace the "pulsing whir" and start a band with that name? -- PLEASE post a SUMMARY of the answer(s) to your question(s)! Unless otherwise noted, the statements herein reflect my personal opinions and not those of any organization with which I may be affiliated.
From: pk on 3 Jun 2010 11:51 Kevin the Drummer wrote: > I'm having trouble with noise in my system. I custom built the system > doing all the usual things to make it quiet, and it was running just > great. It was quiet enough that sitting with my head 1m away from the > system the florescent lights 2m away were louder by far than the > computer. > > Then my ABIT-AV8-3rd-Eye motherboard died and I had to replace it with a > Tyan Tomcat K8E S2865G2NR motherboard. After doing that the machine > made a "whir whir whir ..." sound, with the whirring being about one > second between whirs. I thought I might have damaged something in the > swap, and I thought the new noise was coming from the CPU fan. > > Last night I replaced the old Zalman CNPS7700-AlCu CPU cooler with a > similar Zalman CNPS 7500 AlCu LED CPU cooler. But, when I powered on > the unit I get the same whir. I didn't really want the LED in the CPU > fan, but it turns out that it's giving me a hint as the brightness of the > LED in the CPU fan is pulsing exactly in time with whirring noise. I > wondered if I might be able to get at some fan controls via the BIOS, > and booted into that screen. I found another clue, the whirring is > exactly in time with the system clock, whirring just as each second on > the clock ticks by. > > I put an add-on fan speed control in-line with my CPU fan power. When I > turn the speed control up and down it works as expected, and the normal > fan noise changes with fan speed. But, the whirring noise stays > constant with CPU fan speed. > > The hard drives seem quiet enough, and not the source of whirring. The > case fans are quiet enough that I have to strain to hear them with my > ear right by them. My video card is fan-less. My power supply isn't > making the whirring sounds. > > What am I dealing with here? Do I have a motherboard that causes this? > Are the Zalman fans that I love in all my other systems being upset by > the Tyan motherboard? What else can I do to troubleshoot this? My next > random attempt, half in panic, would be to swap motherboards again. > > Thanks all..... > > Maybe I should embrace the "pulsing whir" and start a band with that name? Maybe it's not your problem here, but could it be plain old "coil noise"? Eg see these articles: http://www.tomshardware.co.uk/forum/20853-44-what-coil-noise http://www.network- technologies.org/Projects/Virtual_Brain_Online.php/article/106/ and also you can google to find many more.
From: bosco on 3 Jun 2010 15:08 I am guessing you are hearing the cpu fan. You can verify by using an old paper towel cardboard tube. Use it as a directional hearing device with one of your case panels off. You should be able to locate the source easily. gl
From: Grant on 3 Jun 2010 18:36 On Thu, 03 Jun 2010 10:39:32 -0500, Kevin the Drummer <nobody(a)cosgroves.us> wrote: >I'm having trouble with noise in my system. I custom built the system >doing all the usual things to make it quiet, and it was running just >great. It was quiet enough that sitting with my head 1m away from the >system the florescent lights 2m away were louder by far than the >computer. > >Then my ABIT-AV8-3rd-Eye motherboard died and I had to replace it with a >Tyan Tomcat K8E S2865G2NR motherboard. After doing that the machine >made a "whir whir whir ..." sound, with the whirring being about one >second between whirs. I thought I might have damaged something in the >swap, and I thought the new noise was coming from the CPU fan. > >Last night I replaced the old Zalman CNPS7700-AlCu CPU cooler with a >similar Zalman CNPS 7500 AlCu LED CPU cooler. But, when I powered on >the unit I get the same whir. I didn't really want the LED in the CPU >fan, but it turns out that it's giving me a hint as the brightness of the >LED in the CPU fan is pulsing exactly in time with whirring noise. I >wondered if I might be able to get at some fan controls via the BIOS, >and booted into that screen. I found another clue, the whirring is >exactly in time with the system clock, whirring just as each second on >the clock ticks by. > >I put an add-on fan speed control in-line with my CPU fan power. When I >turn the speed control up and down it works as expected, and the normal >fan noise changes with fan speed. But, the whirring noise stays >constant with CPU fan speed. > >The hard drives seem quiet enough, and not the source of whirring. The >case fans are quiet enough that I have to strain to hear them with my >ear right by them. My video card is fan-less. My power supply isn't >making the whirring sounds. Yes, I saw this problem with the case fan mobo connection, so I run the case fan from 12V disk drive connector via an adapter. I don't notice the noise from CPU fan (no lights on it wither). > >What am I dealing with here? Do I have a motherboard that causes this? Think it's the mobo, perhaps there's a BIOS option to change it? >Are the Zalman fans that I love in all my other systems being upset by >the Tyan motherboard? What else can I do to troubleshoot this? My next >random attempt, half in panic, would be to swap motherboards again. I wouldn't swap mobo, just run the fan from the disk power 12V, and splice the fan speed monitor wire back to a connector on the mobo if you want to monitor the fan speed or failure. > >Thanks all..... > >Maybe I should embrace the "pulsing whir" and start a band with that name? Bit of a slow beat? Unless that matches your style? :) Grant. -- http://bugs.id.au/
From: Kevin the Drummer on 3 Jun 2010 18:40
bosco <boscopelone(a)yahoo.com> wrote: > I am guessing you are hearing the cpu fan. You can verify by using an > old paper towel cardboard tube. Use it as a directional hearing device > with one of your case panels off. You should be able to locate the > source easily. gl Excellent. I'll try that. Thanks! -- PLEASE post a SUMMARY of the answer(s) to your question(s)! Unless otherwise noted, the statements herein reflect my personal opinions and not those of any organization with which I may be affiliated. |