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PWM output on GT2560
Posted: Mon Nov 21, 2016 7:47 pm
by ryan1977
Hello,
Has anyone else has issues with the PWM output on the GT2560 providing power to a cooling fan? I noticed that my cooling fan was never turning off even after sending an M107 command. The M106 command is working but sending 0% only slows the fan a little bit.
I hooked up an oscilloscope to the output and noticed that there is a PWM signal on the ground line but it only pulls down to 9V (the pulse width is correct but the amplitude only goes from 12V to 9V).
Any ideas? It looks like the PWM signal is not pulling strongly enough to ground.
Ryan
Re: PWM output on GT2560
Posted: Thu Nov 24, 2016 5:54 pm
by ryan1977
Hello all,
Would like to update my own post. I determined the issue to be the Q5 MOSFET. There must have been an internal short on the device. I replaced Q5 with this part:
http://www.infineon.com/dgdl/irlml6246p ... 6878f22621 and everything is working fine now.
Re: PWM output on GT2560
Posted: Thu Dec 01, 2016 4:52 am
by waldamore
i also have issues with the PWM Output on my board. but in my case, there is no power at all!!
the fan wont turn on. even with the gcodes, it wont turn.
i did a messurement: fan1-3 deliveres constant 12v, but the PWM stays at 0v.
can you describe your solution more detailed or do you have any idea about my problem?
thx!!
Re: PWM output on GT2560
Posted: Thu Dec 01, 2016 6:40 am
by waldamore
update: i looked closer to the Q5 microcontoler and it looks burned.
mesured the voltage and sadly i was right: 0,0V
i searched online for a replacement to the broken IRLML6246TRPBF and found this one:
ON SEMICONDUCTOR NTR4501NT1G MOSFET-Transistor, n-Kanal, 3.2 A, 20 V, 80 mohm, 4.5 V, 1.2 V
http://de.farnell.com/on-semiconductor/ ... L6246TRPBF
please tell me, if this one is fine - because a have no clue at all!!
thanks a lot
Re: PWM output on GT2560
Posted: Sat Dec 03, 2016 2:44 pm
by William
waldamore wrote:update: i looked closer to the Q5 microcontoler and it looks burned.
mesured the voltage and sadly i was right: 0,0V
i searched online for a replacement to the broken IRLML6246TRPBF and found this one:
ON SEMICONDUCTOR NTR4501NT1G MOSFET-Transistor, n-Kanal, 3.2 A, 20 V, 80 mohm, 4.5 V, 1.2 V
http://de.farnell.com/on-semiconductor/ ... L6246TRPBF
please tell me, if this one is fine - because a have no clue at all!!
thanks a lot
Hi,
Maybe you can contact your seller to resend a Q5?