Quest M3 fan not working? - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
sternocleido (original poster)

#11: Post by sternocleido (original poster) »

You're welcome! It's good to know that someone puts this information to good use! :)

EspressoForge

#12: Post by EspressoForge »

sternocleido wrote: So, you only need to cut the 300k resistor in parallell with the trim pot. I have just made the modification and can report that it works like a charm! :D
Hi Ivan, thanks very much for the info! I can also report that the mod worked great for me. Not only did it give the fan more adjust-ability (from completely off to full speed), but it also made the max fan speed much higher. No longer will I have to open both doors for my drying phase. Thanks!

My resistor was a different color, but in the same position, see this pic:

Espresso Vision: the perfect cup of coffee starts with understanding your roast
Sponsored by Espresso Vision
sternocleido (original poster)

#13: Post by sternocleido (original poster) »

Great to know that it worked for you as well, Andre! That looks like a 91k resistor (white-brown-orange-gold) - which makes me wonder how many revisions of the internal wiring exist for the M3!..

OldmatefromOZ

#14: Post by OldmatefromOZ »

Hmmm so it seems like this might be a worthwhile mod.

Anyone done this on a 240V Quest? I am lead to believe that it should be the same. The European models would mostly be 240V yes?

It would be nice to not have to open and close lids, as I generally only use minimum air toward the end of drying phase. Also the reports of the max setting giving a higher airflow are enticing as well.

My fan is due for a clean soon so will have to have look while Ive got the covers off.

sternocleido (original poster)

#15: Post by sternocleido (original poster) »

Mine is 240V model :)

OldmatefromOZ

#16: Post by OldmatefromOZ » replying to sternocleido »

Thank you 8)

User avatar
another_jim
Team HB

#17: Post by another_jim »

How can the fan get faster? The resistor seems to be parallel to the pot, allowing for a trickle current when the pot is set down, and the fix is cutting it. That will slow the fan down when the pot is set low, but how can it speed the fan up when the pot is set high?
Jim Schulman

Weber Workshops: tools for building better coffee
Sponsored by Weber Workshops
EspressoForge

#18: Post by EspressoForge » replying to another_jim »

Embarrassingly, I don't exactly know, I'm sad to say my days of circuit design are probably long behind me... I also didn't look much at the fan control circuitry inside, just clipped the resistor and tested! This was after taking probably an hour or more to deep clean all the other parts...coffee oils really start to build up after a while.

Has anyone seen a circuit diagram around for the M3? Would be handy if someone has made one already, maybe looking at that I could figure something out. :)

User avatar
FotonDrv

#19: Post by FotonDrv »

If part of the available power to the fan is being shunted off by the resistor then removing the resistor would mean more power available to the fan motor wouldn't it?
That Light at the End of the Tunnel is actually a train

User avatar
another_jim
Team HB

#20: Post by another_jim » replying to FotonDrv »

That would do it; but I thought the resistor was just shorting out the pot, so the fan could not be turned off completely.
Jim Schulman