1 Topic by knowack (edited by knowack 2015-07-11 02:50:55)

  • knowack
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Topic: G-code fan stopped responding

I recently upgraded my SD4 with an E3Dv6, which required flashing the Printrboard's firmware.  Everything had been working fine until yesterday, when I started having a strange problem with my upgrade:

I finally printed a duct for my g-code cooling fan, and got it installed.  Everything was working correctly (yes I had configured pin 16 in the firmware):  I could turn the fan on and off, and control its speed from the Manual Control screen in R-H.  I could send g-code commands to turn it on and off as well.

After printing my first object with g-code fan control enabled in cooling, my fan is now stuck on at 100%.  Nothing will change the fan speed or turn it off, short of unplugging it from the Printrboard.  I've done some troubleshooting:

1. Turned the printer off, let it sit, then rebooted
2. Having just upgraded to the latest version of R-H, I reverted to the previous version
3. Re-flashed the firmware in the Printrboard
4. Connected to the printer via OctoPi

Nothing seems to work.  Am I chasing some sort of firmware bug?

Is there some way to do a 'factory reset' or otherwise clear the board to do a fresh firmware load?

2 Reply by TickTock

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Re: G-code fan stopped responding

Do you have a multimeter?  Check to see if the gate of the FET is getting driven properly (5V on, 0V off, PWM in between - will look like an intermediate voltage or flickering).  Could be the FET got zapped during handling.  Trace the line from the header back to the FET, it will have three terminals:  Drain (connectect to the fan), VSS, and gate.

3 Reply by knowack

  • knowack
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Re: G-code fan stopped responding

TickTock wrote:

Do you have a multimeter?  Check to see if the gate of the FET is getting driven properly (5V on, 0V off, PWM in between - will look like an intermediate voltage or flickering).  Could be the FET got zapped during handling.  Trace the line from the header back to the FET, it will have three terminals:  Drain (connectect to the fan), VSS, and gate.

Oooh, good idea.  I hadn't thought of the MOSFET.  The voltage to the gate appears to be switching on and off properly; I must have damaged the MOSFET somehow.  The good news is, since the MOSFET failed to the ON condition, my fan is still working.

I ordered replacement MOSFETs from Newark Element 14.  For those interested, the part number is IRLML2060TRPBFCT-ND for the MOSFET.

4 Reply by knowack

  • knowack
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Re: G-code fan stopped responding

All fixed!  I replaced the surface-mount MOSFET, and all is working again. 

Thanks again TickTock for the idea of troubleshooting the MOSFET circuit.

5 Reply by EagleSeven (edited by EagleSeven 2015-07-18 14:18:35)

  • EagleSeven
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Re: G-code fan stopped responding

That's Great ! smile

I'm curious, is there a Fan cooling that circuit board in your printer ?
If not, it may need one ?

Our CTC has a very Noisy little fan for that. tongue

CTC Printer
Modifications Added

6 Reply by knowack

  • knowack
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Re: G-code fan stopped responding

There's a fan for the motherboard.  I'm sure I just zapped the MOSFET somehow when I was playing with the fan wiring.