Mahlkönig Vario Sparking from Circuit Board - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.
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Team HB

#11: Post by Jeff »

DC motor, 230 V mains, full-wave rectifier, about 325 V.

I don't recall if that is a DC motor or not.

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#12: Post by Nunas »

It looks very much like a DC motor to me. The wires to it are red and black, and there appears to be a red dot on the motor, which to me would indicate the positive lug.

The DC voltage on the meter seems reasonable to me, with a couple of assumptions. Although the average DC voltage out of the flipped sine wave, after the bridge, would be about 220 VDC, in a typical bridge rectifier power supply with an electrolytic capacitor, the output would be higher, as the voltage peaks are higher than RMS by the square root of two (~1.41). So, about 310 volts, which isn't far from what the OP measured.

That said, I've no idea what might be the problem, given what we know so far. :wink:

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BaristaBoy E61

#13: Post by BaristaBoy E61 »

I'm not buying anything without a full electronic schematic and parts list.
Where's the OP, Europe or NA?
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"


#14: Post by Oskuk »

These are just toys. But, as many says: easy to repair. Just change the main board, get new motor, new belt, and -new burr chamber-cradle, that newer is metallic, as othervise the plastics just bend and you never get the good result.
But then the price is such that you get real grinder for the parts. Ask how I know?
I have one of these, reminding what not to buy ;-)

weastman (original poster)

#15: Post by weastman (original poster) »

As many have written this is DC motor and given 240V is rectified 310-320V seems about right.
I did a little more running and I think the motor has a small short in the windings, this is only going to get worse and is currently at least a ear-sore at most a danger.

I therefore have now bought a new motor and fitted and all seems well. Fingers crossed that is it fixed for now.
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#16: Post by Oskuk »

These are, in many ways intersting ones -at least some masochistic way. I got again another broken Vario, which was "probably motor" for free. This was stuck of coffee, but coils are ok, and motor runs, but not the way these should. BTW the belts are harder to find nowadays here in Nordic, or plenty pricey. It is kind of funny that manufacturer always says "change the motor", as if the coils are measred ok, and the collectors are ok, what can be the thing there are lacking? Other grinders get bad start-caps, or run-caps and then they go powerless.

My original Vario, plenty burned components and burned motor-coils, next one just powerless motor, and this third has too tired motor.

I put these runners forward to mokapot etc. use, but the original keeps here with me -as a faiulure-statue of free will of buying bad items ;-)