fan control burned out?

[joergen 2]

I did a mistake while updating the fan shroud around the print head:

I installed a new fan, and accidentally reversed the polarity, and it fried itself with smoke.

Then I went back to the original fan, only to discover that the fan control didn't work anymore, and the fan always runs when the board is powered up (could be worse).

Did I just fry the BD679 (darlington transistor)? is the BD679 actually driving the cooling fan (I would assume it does), or did I fry more than the transistor?

advice?

joergen

[owen 19]

I thought fans only usually have a coil in them and wouldn't be affected by reverse polarity except that they'd run backwards.

[joergen 2]

Fans have most times a small pcb, and a SMD control chip, which in my case went up in smoke... no smoke from the main board... just looking for confirmation if the BD679 is doing the fan control or not...

[Daid 306]

Fans have most times a small pcb, and a SMD control chip, which in my case went up in smoke... no smoke from the main board... just looking for confirmation if the BD679 is doing the fan control or not...

The PCB on those fans does the PWM, which is not very wise, as it does the same as the PWM on the UM board.

The BD679 is turning the fan on/off. So if it's always on then it's most likely fried.

It could be that the output of the Arduino is fried, easy to test, turn on the board without the Arduino connected. If the fan turns on, the BD679 is fried.

[joergen 2]

The BD679 is turning the fan on/off. So if it's always on then it's most likely fried.

It could be that the output of the Arduino is fried, easy to test, turn on the board without the Arduino connected. If the fan turns on, the BD679 is fried.

It's fried, thanks for confirming... now I need to find a new one.

[Daid 306]

 

http://reichelt.de/

sells them for 29 cents, which is cheaper then Farnell. They also have affordable nuts&bolts, and loads of other stuff.

[joergen 2]

http://reichelt.de/ sells them for 29 cents, which is cheaper then Farnell. They also have affordable nuts&bolts, and loads of other stuff.

They are in Germany/Europe, I'm in the US/NYC... I'll find a local supplier...