Advice needed on wiring a fan

masonic · 17-04-2008, 03:46 PM

Hi there - this is my first post -
so I will get straight to the point:
I have a dell poweredge server (600sc), but the fans are terribly noisy I mean absolutely so you cant think in the same room. Anyway I discovered that if I link the fan up to a 5v line on the IDE power connector it slows the fan and makes it acceptably quiet - trouble is that to do this I had to remove the tachometer sensor wire (white wire in the middle) and just attatch the black and red wires to the relevent IDE power - The problem now being that at boot time the BIOS halts and says rear system fan and front system fan not connected press f1 to continue. There is no option at all in the bios to change this behaviour so I need a fix via a hardware solution

So the question is - if I keep the fans hooked up to 5v can I put the white wire back onto the board where it should go and that would solve the problem? What sort of current does that white wire carry? will it blow the board or something if I do that ?

I can actually get away with no case fans on the server if necessary as I have adequate cooling on the processor and the psu is quiet enough its just the rear and front case fans I am concerned with

If anyone can answer my questions or come up with a good solution of how to stop the "press F1" thing happening I will be extremely grateful
Thank you !

the site looks fantastic BTW

ShrimpBrime · 17-04-2008, 11:38 PM

In the bios go to hardware monitor. Then set the fan sensor to ignor. I would suggest you go to newegg and buy fans that are made to push lots of air and are quite at the same time. They do make them.
Swapping the fans current is not a good thing. the five amp line uses more amps and there for will decrease the life of the fans.

masonic · 17-04-2008, 11:42 PM

Ok thanks for the reply.
There is no setting in the BIOS to affect the fans. Dell BIOS's are notoriously light on features and there is absolutely no way on a Poweredge 600sc to set it so the sensor is ignored

But I take the point about the fans its just I have already spent £40 on a huge zalman heatsink and a quiet cpu fan and also £7 on a quiet psu fan - I am loathe to spend much more on other fans if I can help it.

ShrimpBrime · 18-04-2008, 05:18 AM

In the bios where it displays the fan speed. Highlite and use the + or - key and see if it has an ignor option.
Yea some times a little $$ and tlc will take you deep into your thoughts without that buzz in the background! :]'

teraformer · 18-04-2008, 10:58 PM

On the other hand just make yourself a molex onverter cable

masonic · 19-04-2008, 07:51 PM

yes that is the point, and if I do that, then exactly how is the motherboard supposed to detect the fan - What kind of molex adaptor do you mean there are many many available! The whole point of the original post being: If I make an adaptor can I run the fan on 5v AND also put the white wire (the tachometer sensor) back onto the system board so that it will detect the fan otherwise I keep having to press F1 and there are no settings concerned with fan detection in the BIOS or even any display of fan speeds or temperatures!

My point being does anyone know of a hardware fix to this - I need an answer from someone that knows about the voltage and what will happen if I switch to 5v and the white wire goes back on to the board

ShrimpBrime · 20-04-2008, 09:52 PM

Quote:

Originally Posted by masonic

yes that is the point, and if I do that, then exactly how is the motherboard supposed to detect the fan - What kind of molex adaptor do you mean there are many many available! The whole point of the original post being: If I make an adaptor can I run the fan on 5v AND also put the white wire (the tachometer sensor) back onto the system board so that it will detect the fan otherwise I keep having to press F1 and there are no settings concerned with fan detection in the BIOS or even any display of fan speeds or temperatures!

My point being does anyone know of a hardware fix to this - I need an answer from someone that knows about the voltage and what will happen if I switch to 5v and the white wire goes back on to the board

the fan out put is 12 volts from the mobo. The sensor is what you need pluged into the mobo so it know's a fan is there. Usually the wire is white or yellow. If you run the 5 volts from the rail the fan will be slower and quiter.
The mobo puts 12 volts out. so how are you gonna worrie bout 5 volts that you wont plug into the board again? Take the power from a 5 volt rail (the power suplly may have a config) splice into that. solder it for a good connection. lil black tape around the soldier. Use the unspliced plug with the yellow or white wire and plug it into the mother board. the sensor wire will tell the mobo the fans is spinning and the warning may go away. Unless the fan speed is too low you may also get a warning any way.
The sensor wire doesn't carry the fans current. It's just a sensor.

17-04-2008, 03:46 PM	#1 (permalink) Top
masonic Geek Trainee Join Date: Apr 2008 Posts: 4 Status: Offline	Advice needed on wiring a fan Hi there - this is my first post - so I will get straight to the point: I have a dell poweredge server (600sc), but the fans are terribly noisy I mean absolutely so you cant think in the same room. Anyway I discovered that if I link the fan up to a 5v line on the IDE power connector it slows the fan and makes it acceptably quiet - trouble is that to do this I had to remove the tachometer sensor wire (white wire in the middle) and just attatch the black and red wires to the relevent IDE power - The problem now being that at boot time the BIOS halts and says rear system fan and front system fan not connected press f1 to continue. There is no option at all in the bios to change this behaviour so I need a fix via a hardware solution So the question is - if I keep the fans hooked up to 5v can I put the white wire back onto the board where it should go and that would solve the problem? What sort of current does that white wire carry? will it blow the board or something if I do that ? I can actually get away with no case fans on the server if necessary as I have adequate cooling on the processor and the psu is quiet enough its just the rear and front case fans I am concerned with If anyone can answer my questions or come up with a good solution of how to stop the "press F1" thing happening I will be extremely grateful Thank you ! the site looks fantastic BTW

19-04-2008, 07:51 PM	#6 (permalink) Top
masonic Geek Trainee Join Date: Apr 2008 Posts: 4 Status: Offline	yes that is the point, and if I do that, then exactly how is the motherboard supposed to detect the fan - What kind of molex adaptor do you mean there are many many available! The whole point of the original post being: If I make an adaptor can I run the fan on 5v AND also put the white wire (the tachometer sensor) back onto the system board so that it will detect the fan otherwise I keep having to press F1 and there are no settings concerned with fan detection in the BIOS or even any display of fan speeds or temperatures! My point being does anyone know of a hardware fix to this - I need an answer from someone that knows about the voltage and what will happen if I switch to 5v and the white wire goes back on to the board Last edited by masonic; 19-04-2008 at 07:56 PM.

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17-04-2008, 11:38 PM	#2 (permalink) Top
ShrimpBrime Geek Trainee Join Date: Jan 2008 Age: 29 Posts: 43 Times Helpful: 2 Status: Offline	In the bios go to hardware monitor. Then set the fan sensor to ignor. I would suggest you go to newegg and buy fans that are made to push lots of air and are quite at the same time. They do make them. Swapping the fans current is not a good thing. the five amp line uses more amps and there for will decrease the life of the fans.

17-04-2008, 11:42 PM	#3 (permalink) Top
masonic Geek Trainee Join Date: Apr 2008 Posts: 4 Status: Offline	Ok thanks for the reply. There is no setting in the BIOS to affect the fans. Dell BIOS's are notoriously light on features and there is absolutely no way on a Poweredge 600sc to set it so the sensor is ignored But I take the point about the fans its just I have already spent £40 on a huge zalman heatsink and a quiet cpu fan and also £7 on a quiet psu fan - I am loathe to spend much more on other fans if I can help it.

18-04-2008, 05:18 AM	#4 (permalink) Top
ShrimpBrime Geek Trainee Join Date: Jan 2008 Age: 29 Posts: 43 Times Helpful: 2 Status: Offline	In the bios where it displays the fan speed. Highlite and use the + or - key and see if it has an ignor option. Yea some times a little $$ and tlc will take you deep into your thoughts without that buzz in the background! :]'

18-04-2008, 10:58 PM	#5 (permalink) Top
teraformer Geek Trainee Join Date: Apr 2008 Posts: 46 My Mood: Cheerful Status: Offline My Computer	On the other hand just make yourself a molex onverter cable

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