how to bypass cooling fan on demand speed?

[fddizon]

hi,

i am having thermal problem with this laptop -sony vaio vpcee32fx.
i'd like to bypass the on demand speed, would like to make it at full speed
always.

there are 3 wires from mobo to fan.

thanks for any solution

[Lumberjack777]

Re: how to bypass cooling fan on demand speed?

hi,

i am having thermal problem with this laptop -sony vaio vpcee32fx.
i'd like to bypass the on demand speed, would like to make it at full speed
always.

there are 3 wires from mobo to fan.

thanks for any solution

1 wire is power. 1 is ground. and the other is speed control. If you disconnect the speed control wire, it should run at full speed.
On a DV9000 there are 4 wires on the fan. The red is the power and the black is the ground. What I do since I can't quite handle the full speed sound of the fan is to add a 6 ohm resistor on the red wire. Then it's always on and cools the cpu and the gpu, but it's running at a level I can tolerate.
If you have a red and black wire that's probably the 2 that you need. Even if that's not the 2. It won't hurt the fan, it just won't run. You need to find the power and ground. Mine are red and black.

[fddizon]

Re: how to bypass cooling fan on demand speed?

1 wire is power. 1 is ground. and the other is speed control. If you disconnect the speed control wire, it should run at full speed.
On a DV9000 there are 4 wires on the fan. The red is the power and the black is the ground. What I do since I can't quite handle the full speed sound of the fan is to add a 6 ohm resistor on the red wire. Then it's always on and cools the cpu and the gpu, but it's running at a level I can tolerate.
If you have a red and black wire that's probably the 2 that you need. Even if that's not the 2. It won't hurt the fan, it just won't run. You need to find the power and ground. Mine are red and black.

lumberjack,

thanks for the idea. i remember way back doing that, but the laptop gave me an error to check the fan. it wont let the laptop to boot. i hope this sony vaio laptop is not the same.

thanks

[fddizon]

Re: how to bypass cooling fan on demand speed?

can i put carbon type resistor 1/8 watts?

[Lumberjack777]

Re: how to bypass cooling fan on demand speed?

can i put carbon type resistor 1/8 watts?

Yes, and you can experiment. I started with 2 ohms. Too loud. Then 4 ohms. Same thing. I settled for a 6 ohm resistor for the balance between cooling and noise. I used GPU-Z and CPU-Z to monitor the temps also until I got just the right balance on my temps and fan noise.

[Th3_uN1Qu3]

Re: how to bypass cooling fan on demand speed?

On 3-wire fans the middle wire is RPM sensing, not speed control. Speed is controlled by varying the DC voltage on the power wire. You can disconnect the power wire (red) and wire it straight to a 5 volt supply for full speed. Check where you wire it beforehand - you don't want to wire it to the standby power supply and have it spin even when the laptop is off.

[c_hegge]

Re: how to bypass cooling fan on demand speed?

Precisely. That 3rd wire is indeed a tachometer. Fans that have their own speed controllers have four wires.

I modded my my Toshiba A200's 3 pin fan this way. I used the HDD's SATA power connector as a source of 5V.

[Lumberjack777]

Re: how to bypass cooling fan on demand speed?

On 3-wire fans the middle wire is RPM sensing, not speed control. Speed is controlled by varying the DC voltage on the power wire. You can disconnect the power wire (red) and wire it straight to a 5 volt supply for full speed. Check where you wire it beforehand - you don't want to wire it to the standby power supply and have it spin even when the laptop is off.

Ahhhhh, interesting. Good to know. Thanks for the correction.

On my DV9000's, the GPU's are all running at 40c to 50c now. They get close to 60 on my BurninTest 3D Graphics max load program. One customer said before I did the fan mod it hit 88c

I had to reflow it for him. He uses a cooling pad with the fan mod, and said it has never gotten above 50c

[fddizon]

Re: how to bypass cooling fan on demand speed?

On 3-wire fans the middle wire is RPM sensing, not speed control. Speed is controlled by varying the DC voltage on the power wire. You can disconnect the power wire (red) and wire it straight to a 5 volt supply for full speed. Check where you wire it beforehand - you don't want to wire it to the standby power supply and have it spin even when the laptop is off.

does the 3 wired fans all the same regardless of wire color? center wire is colored red, yellow and black on sides.

[spidey]

Re: how to bypass cooling fan on demand speed?

does the 3 wired fans all the same regardless of wire color? center wire is colored red, yellow and black on sides.

never look the colors, always measure.


And for a full speed, get +5v from usb +.

[fddizon]

Re: how to bypass cooling fan on demand speed?

how about getting 5v from a usb port? will it degrade the port for using it?

[Elysarian]

Re: how to bypass cooling fan on demand speed?

I was always under the impression that decent fan controllers used a PWM circuit to vary the speed, not a varying DC level?

the higher the mark/space ratio (more "on" time) the faster the fan will spin as the voltage average will be higher.

This is done to avoid a scenario where the fan stalls due to insufficient voltage.

Of course modding the fan to have a permanent voltage instead of the output from the speed controller will still cause the fan to run at a constant speed though.

I can't see that the tiny current drawn by a small fan would affect the USB ports too much myself unless you're close to maxing them out already.

[Th3_uN1Qu3]

Re: how to bypass cooling fan on demand speed?

how about getting 5v from a usb port? will it degrade the port for using it?

I've done it before and it works just fine.

I was always under the impression that decent fan controllers used a PWM circuit to vary the speed, not a varying DC level?

Only on 4-wire fans, which have a speed controller built-in. You'll have a hard time getting a normal (2-wire or 3-wire) fan to accept a PWM signal. On the other hand... on non-PWM fans that varying DC level *is* generated via PWM internally in the drive IC.

[c_hegge]

Re: how to bypass cooling fan on demand speed?

how about getting 5v from a usb port? will it degrade the port for using it?

It will slightly reduce the amount of current the port can supply, but not by much. If you just use the port for something less power hungry (like a mouse), it will be fine.

does the 3 wired fans all the same regardless of wire color? center wire is colored red, yellow and black on sides.

It's probably the yellow wire, but as others have said, measuring the voltage is always a good practice. Sometimes, the fans will also have the wires labelled on the PCB