GT2560 PWM Fan always rotating

[Depax]

Hi,
After replacing the filament fan (PWM connector) with a new now the PWM fan is always rotating, even the printer is idle.
If I increment the fan speed in the menu it increase the speed. It seems the "0" PWM status it's no mora at "0".
I've checked Q5 and seems to be good.
I have a Geeetech Prusa I3 pro b with GT2560.
I tried to reflash firmware but with no results.

Does anyone have an idea about this issue?

Thanks & kind regards,
Alex

[Mark]

I remember the "0" on the repetier host menu is not the actual 0 speed, you can slow it down but as you said, will not stop.
check this setting:

QQ截图20160208204635.jpg (38.48 KiB) Viewed 18128 times

[Depax]

Hi Mark,
thanks for your quick reply.
I don't think it's such case because the fan start rotating as soon I power on the printer, even without pc connected. BTW this setting was already unchecked.
If I remember correct the fan wasn't start at power on and I was able to turn it on by me FAN SPEED menù item under CONTROL -> TEMPERATURE.
Now it starts immediatly at around 50% and by change FAN SPEED setting you can increase it from 50% to 100%

I have also tried differen fan with 2 and 3 pin but all behaves in the same manner.

Regards,
Alex

[Mark]

how's the old fan? is it still the same manner? werid...

[Depax]

Even the old one always rotates...
This is why I'm thinking about a problem on Gt2560...
Can a wrong insertion of a 3 pin fan damage the board? If I made such mistake the inversion was between +12 and tachiometric signal (ground is in the middle)
The problem was the wrong pinout of gt2560 schematics I downloaded..
But I remeber at the beginning the old fan was connected in wrong way due to schematics, then I found out with a multimeter the error and after reversing the pin the fan was working well..
so weird....

Thanks & Regards,
Alex

[Mark]

Yeah the signal on the fan connector is not used, just need connect the fan to the + and - of the connector.

[smokehead]

Hello,

I have exactly same problem, the PWM fan is always on till yesterday. My all fans... I have about 10, they rotate from 0 -255 doesnt matter.
Any solution? I chenged firmware again but didnt work.

[bang]

Hello,

I have exactly same problem, the PWM fan is always on till yesterday. My all fans... I have about 10, they rotate from 0 -255 doesnt matter.
Any solution? I chenged firmware again but didnt work.

So did you check the slicing setting in the above picture?

[smokehead]

I use cura, and i know that setting, anyway when You turn on printer fan should not working in pwm when on LCD You have "0". My is working.

[bang]

Alright...I guess the mosfet controlling the PWM fan may be not working properly.
Check this post:
http://www.geeetech.com/forum/viewtopic ... 24&t=17886