mcp-655 pwm problem

[dima202]

Hello, I am doing my first watercooling build and ran into the problem where the pump is not registering rpm on my motherboard sensors. I made sure that the green wire is in the righr position and blue wire is just next to it. But motherboard bios says n/a and speedfan says 0rpm.

I can feel that thepump is working...

[airdeano]

the pump is running 100% because the control wire is an "open" circuit.

silly question, tried another fan header? and what motherboard, not all can support

PWM, may have a header, but not the "control"

 

 

airdeano

[dima202]

Hey airdeano,

This is an asus p6tdeluxe v2 mobo

I am controlling a fan I have mounted to the north bridge.

I tried 3 fan headers cpu, chasses and power

[dima202]

At this point I think the pump pwm sensor is not working.

Will contact frozencpu for refund.

[dima202]

I got a new pump.

While testing I hooked it up to mobo 3 pin connector and the pump shut off. I unplugged it from the mobo and it started working.

Note - during testing mobo was turned off.

Then I plugged the whole sysem to power, but pwm was still not registering.

After this, the pump could be controlled manually through pwm cables. If I short curcuit them, the pump speeds up, if I ground the green while, pump shuts off.

So I think I killed the pwm by plugging it into a 3 port mobo connector instead of the 4 port cpu connector.

[airdeano]

I got a new pump.

While testing I hooked it up to mobo 3 pin connector and the pump shut off. I unplugged it from the mobo and it started working.

Note - during testing mobo was turned off.

Then I plugged the whole sysem to power, but pwm was still not registering.

After this, the pump could be controlled manually through pwm cables. If I short curcuit them, the pump speeds up, if I ground the green while, pump shuts off.

So I think I killed the pwm by plugging it into a 3 port mobo connector instead of the 4 port cpu connector.

 

most likely not.. the only difference in the header or pin-out is the fourth wire is

for PWM control. the 3-pin would just apply 12v to the device. now trying to voltage

control a PWM circuit can result in damages. PWM does not like voltage control.

 

airdeano

[dima202]

Then, why am I not getting a reading in bios?

I hooked it up to cpu fan header but I get "N/A" :(

[airdeano]

a lot of reasons.. not all motherboards can support all PWM. Swiftech is getting

a lot of push back because the PWM pump is not being seen (and your PWM

pump is... Swiftech) Swiftech Troubleshooting (seems there is not support for

the PWM D5 at this time).

 

 

"All the devices connected to my PWM splitter work at 100% but I cannot vary their speed"
 

1. Check that the splitter mini-4 pin PWM signal cable is correctly connected to the CPU_Fan connector of the motherboard
2. Enable "Manual Fan Control" in the motherboard BIOS

"The device(s) connected to my PWM splitter do not work"
 

1. Check that the splitter power cable is connected to the power supply
2. Check that the non-functioning device female 4-pin connector is correctly inserted in all 4 pins of the splitter connector: in effect, it may be possible to inadvertently offset the female connector by one pin by slightly forcing its insertion, so be careful about this!

"I am getting a "CPU fan error" when I turn on the computer"
 

1. Make sure that a device is connected to channel 1 of the PWM splitter. If the motherboard CPU_Fan header does not read an RPM signal, it will return such error by default.
2. Check that the device connected to Channel 1 of the PWM splitter is correctly inserted in its connector.
3. Check that the power cable of the PWM splitter is connected to power supply.

"I connected the PWM splitter to an auxiliary 4-pin connector that was indicated as PWM capable by my Motherboard manual, but I can't vary the speed of my devices"
 

1. Other than the CPU_Fan connector which is PWM enabled by default, most of the motherboards 4-pin connectors feature two methods of speed adjustment in order to allow control of both types of fans, the 3-pins which are voltage controlled, and the 4-pins which are PWM controlled. As a result, the PWM functionality must be enabled in the BIOS before it can actually work. Please consult your motherboard manual for a "how To".
2. Since the "CPU_Fan" motherboard connector is PWM enabled by default, we recommend that you connect the splitter to the CPU_Fan connector in order to ascertain its functionality.

"I am connecting the splitter to a PWM fan controller instead of the motherboard, and it doesn't work"
 

• Not all PWM fan controllers are compatible. Please read this white paper for further explanations and a list of compatible devices. 

 

airdeano

[dima202]

Okay, I guess I ameout of luck until I can get some hardware to work properly with pwm.

Is there a way to force pump to 100% in the meantime?

[dima202]

I think it might already be 100% because when unplugged pump slows down to what I believe is 60%

[dima202]

I checked the manual of the mobo and it specifically talk about the 4 pin pwm connector.

From the information I gathered the 2 types of pwm are directly changing voltage and actually sending signal to the motor.

It seems that this motherboards CPU connector should be real pwm.

 

Am I mistaken?

 

Attached is the page showing the pwm connector.

[Ghost]

.

PWM is "Pulse width modulation". There is only one type. The other type of control is just changing the voltage. As your motherboard has a fourth pin then it can "create" a PWM signal.

[dima202]

Great, so now we know that the motherboard truly supports PWM.

So why would the pump not register? This is the 2nd pump now...

I do notice I get better speed if I plug it in. If it take it out during operation, the pump slows down.

[Ghost]

Great, so now we know that the motherboard truly supports PWM.

So why would the pump not register? This is the 2nd pump now...

I do notice I get better speed if I plug it in. If it take it out during operation, the pump slows down.

Make sure your motherboard drivers and software is up-to-date and installed. Try to use your motherboard software to control the pump. Look around your BIOS. Maybe there's a setting you have to switch on. You can also usually control fan speeds in the BIOS.

[airdeano]

I checked the manual of the mobo and it specifically talk about the 4 pin pwm connector.

From the information I gathered the 2 types of pwm are directly changing voltage and actually sending signal to the motor.

It seems that this motherboards CPU connector should be real pwm.

 

there are two versions of that specific motherboard.

both share the same for fan control..

 

Is Power Fan Speed enabled? if disabled, please enable it for RPM sensing.

is CPU QFAN Control enabled? if disabled, please enable it for profile speed control.

3-84 and 3-85 of the Users' Manual.

 

airdeano