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Windows 7: Fan voltages problem

15 Jan 2014   #1

Desk1 8 Pro / Desk2 7 Home Prem / Laptop 8.1 Pro all 64bit
 
 
Fan voltages problem

Am fixing a friends older Compaq some idea of the specs in the Speccy snip/s.
Problem is the CPU is running rather hot average 35C at idle and up to 60C on scans and net searches.

I have cleaned everything redone the compound with Arctic Silver and reseated all the plugs etc etc

Now the problem is the case and CPU fans are not running fast enough - the volts at the 24 pin are fine - jut on 5.06v each red. Now the volts at the fan headers both the CPU and back case fan are 4.6v and I know they can run faster because I have had them out and un on my test PSU.

So any idea on why the volts are dropping from the 24 pin to the headers??

CPU fan runs full blast on power up then slows to a steady - what I can only describe as what one would exect on idle.
Temps can be seen in the pics and the discrepsancy or so it seems with the volts whetaer tis is Specy or the machine I don't know.




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My System SpecsSystem Spec
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15 Jan 2014   #2

Windows 7, 64 bit Home SP1, Win 8.1.1 Pro 64 bit
 
 

Maybe power supply problem. Many factory PC's have marginal power supplies and over time they can deteriorated and unable to handle the power load. One area to look at. If you have another power supply you can use in the PC, for testing, that would be one thing to try.
My System SpecsSystem Spec
15 Jan 2014   #3

Desk1 8 Pro / Desk2 7 Home Prem / Laptop 8.1 Pro all 64bit
 
 

Thanks Jack I didn't get a mail to let me know you had replied mate.
The PSU checked out fine although the watts are a bit on the pathetic side at 228.

Still since then I have installed the rear fan to a Molex connector and it is running as fast as it should and dragging a little more air albeit it hot through the case which is sadly lacking in a lot of inlet venting.

I also installed CPUID HWMonitor and the temps now are as in the pic the only thing is the two cores are quite different temps I expected some but 10C has got me wondering if the CPU is on the way out?
The machine is a tiny bit noisier but as long as the temps are down eh?
I think Speccy could do with bit of work on it to be honest as it is still showing 35C!

But thanks again for chipping in - appeciate it


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My System SpecsSystem Spec
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15 Jan 2014   #4

Windows 7, 64 bit Home SP1, Win 8.1.1 Pro 64 bit
 
 

Power supplies, such as the one you have are marginally acceptable when new, but given some age it may have deteriorated somewhat. I would still try it with a known good power supply and see how it acts and how the fan connector voltages are on the motherboard.

Given there may be other component issues (aging) that may also be contributing to the overall picture.

Thanks for the rep, too

Jack
My System SpecsSystem Spec
15 Jan 2014   #5

Desk1 8 Pro / Desk2 7 Home Prem / Laptop 8.1 Pro all 64bit
 
 

Quote   Quote: Originally Posted by fireberd View Post
Power supplies, such as the one you have are marginally acceptable when new, but given some age it may have deteriorated somewhat. I would still try it with a known good power supply and see how it acts and how the fan connector voltages are on the motherboard.

Given there may be other component issues (aging) that may also be contributing to the overall picture.

Thanks for the rep, too

Jack
No probs mate I suspect you are on the money there too with the aging mobo
My System SpecsSystem Spec
16 Jan 2014   #6

Win8/8.1,Win7-U64, Vista U64, uncounted Linux distor's
 
 

Have you checked the BIOS and all fan control software that may be installed?

If all fans spin up to full rpm at POST that should indicate adequate voltage. If the fans slow down after POST then it's a BIOS setting or software setting.
My System SpecsSystem Spec
16 Jan 2014   #7

Desk1 8 Pro / Desk2 7 Home Prem / Laptop 8.1 Pro all 64bit
 
 

Yes I checked to see if there was any fan control in the BIOS but nothing that I could see and the fan surge on power up and then reverting back to an idle speed is something I don't understand . Perhaps there is fan control in the BIOS but where I don't know.
The CPU fan header is a three pin one with the fan having red, black, and blue leads which again is odd coding to me but at least the machine going reasonably well .
my fried has taken it back and if he brings it back at any time I shall have to test that header pin that the blue lead goes to to find out just what volts are there.

Anyhow I fixed extra fans in and it has brought the temps down to 30C on one core and 40C on the other which again i think is rather odd but at least it isn't hitting 50 - 66C now even in the very hot conditions we have right now.
My System SpecsSystem Spec
16 Jan 2014   #8
Microsoft MVP

Windows 7 Ultimate X64 SP1
 
 

If you work on it again, there should be AMD Cool'nQuiet. That's the AMD fan control, you can disable it.
My System SpecsSystem Spec
16 Jan 2014   #9

Desk1 8 Pro / Desk2 7 Home Prem / Laptop 8.1 Pro all 64bit
 
 

Quote   Quote: Originally Posted by Britton30 View Post
If you work on it again, there should be AMD Cool'nQuiet. That's the AMD fan control, you can disable it.
Thanks Gary I probably will be seeing it again especially as the weather is like it is at the moment.
My System SpecsSystem Spec
17 Jan 2014   #10
Microsoft MVP

Windows 7 Ultimate X64 SP1
 
 

OK, with Cool'n'Quiet enabled with a 3-pin connector, fan speed is controlled by varying the voltages. In fact voltage is used on all speed controlled fans with 3 connectors.

They are +V, -V, and RPM sensor.
My System SpecsSystem Spec
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 Fan voltages problem




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