Page 1 of 1
GT2560 : no control over PWM-Fan
Posted: Tue Jul 05, 2016 12:38 am
by overkill69
Hello,since 2 days I lost controll over the PWM fan.The fan start spinning at full throttle afer power on the printer (Prusa I3b).Tried to send M107 - no reaktion - the manual controll slider in repetier host isn´´t working too.Reset-button on the printer LCD-Panel (reboot) doesn´t solve the problem.
Re: GT2560 : no control over PWM-Fan
Posted: Tue Jul 05, 2016 11:21 am
by William
overkill69 wrote:Hello,since 2 days I lost controll over the PWM fan.The fan start spinning at full throttle afer power on the printer (Prusa I3b).Tried to send M107 - no reaktion - the manual controll slider in repetier host isn´´t working too.Reset-button on the printer LCD-Panel (reboot) doesn´t solve the problem.
Hi,
You can refer to this article to see if the mosfet was broken:
http://www.geeetech.com/forum/viewtopic ... 24&t=17886
Re: GT2560 : no control over PWM-Fan
Posted: Wed Jul 06, 2016 2:17 pm
by overkill69
Hi, Thank you for your fast reply - there is no optical damage on the MosFet - but I checked with a DMM - there is a short between source,Drain and Gate.I need a working Board.
Re: GT2560 : no control over PWM-Fan
Posted: Thu Jul 07, 2016 6:04 pm
by William
overkill69 wrote:Hi, Thank you for your fast reply - there is no optical damage on the MosFet - but I checked with a DMM - there is a short between source,Drain and Gate.I need a working Board.
Sorry,i don't understand what you exactly mean.
Re: GT2560 : no control over PWM-Fan
Posted: Mon Jul 11, 2016 5:41 pm
by overkill69
The positive (+) cable from the Fan is connected to +12Volt - the Negative ist connected to the PWM output signal from the mosfet transistor - the mosfet ist controlled by the PWM-Pin from the Atmel (gate).If the mosfet has a short between drain and source - the negative connector of the fan is permanetly on ground.The Atmel cpu has no control to switch the fan off,or reduce the RPM via changing the PWM signal.
Re: GT2560 : no control over PWM-Fan
Posted: Tue Jul 12, 2016 10:52 am
by William
overkill69 wrote:The positive (+) cable from the Fan is connected to +12Volt - the Negative ist connected to the PWM output signal from the mosfet transistor - the mosfet ist controlled by the PWM-Pin from the Atmel (gate).If the mosfet has a short between drain and source - the negative connector of the fan is permanetly on ground.The Atmel cpu has no control to switch the fan off,or reduce the RPM via changing the PWM signal.
You are right.But this short circuit problem must be caused by the mosfet itself,in other words,maybe the components in the mosfet has broken,so it brings the short circuit between drain and source.And we just need to exchange another mosfet it can be work,am i right ?
Re: GT2560 : no control over PWM-Fan
Posted: Tue Jul 12, 2016 4:48 pm
by overkill69
Yes,that is right, the printer is in warranty, so i need a working Bord for exchange. I'm in contact with Lemon Wang from geeetech, maybe he can send me a mail how i get a working board.