Issue with pwm fan output

dc42

That's the right mosfet. Small MOSFETs are quite easily damaged by static charge until they have been connected in place.

MrBlom

ok i have one more i will test that one
Thanks for the help

MrBlom

haha they are relay small
i got 3 of them and two of them jumped away in the installing process

i also think i damaged the solder pads when removing the first one
so its extra hard to get it in place

i need to order 3 more and make a last try

dc42

I don't advise trying to remove those mosfets without hot air desoldering equipment, because you need to heat all 3 pads at once.

MrBlom

well im learning by doing
i did damage the 2 lower pads they are gone

so i guess i have to live with it ?
or can i connect them to something else ?

this makes my magnet project a bit harder
no i only have 2 fan ports and them are needed to the fans
also the heater ports is all out
can i use a external board/mosfet to control the magnet on/off(24v)
or do i need to get a Duet2/5 board ?

a hot air gun is on top of my shopping list now

Thanks for the help
Regards
Jens

dc42

If you are looking for an SMD hot air reworking station, the 852D+ isn't bad for a budget unit.

If you look at the Duet WiFi schematic (see https://duet3d.com/wiki/Source_Files for links) then you can see which components the fan mosfet is connected to. You could glue the new mosfet dead bug style to the board and then use wires to connect it.

MrBlom

thank dc42
been looking at the drawings and this looks correct to me
see pic
https://www.dropbox.com/s/5hx8kb6vppcssvw/likethis2.jpg?dl=0

Please let me know what you think
Thank you
regards
Jens

dc42

That looks correct to me too.

MrBlom

Thank you !

MrBlom

It works yeah!
thanks for the help

it's not pretty but it works
https://www.dropbox.com/s/zljrxege31854qq/2017-04-26%2018.55.36.jpg?dl=0

Thanks again for the help