I've bought and just received the Mahlkönig K30 Vario.

When I try to grind, the display is blank/empty and it won't grind.

Does anyone have any idea about why this is? I have followed the instructions and there is no relevant troubleshooting.

Do you have the hopper in place? I believe that there's a safety interlock that will cause the display to remain blank and the grinder not to function unless the hopper is properly attached, or the interlock is bypassed with a toothpick or other item.

That should be OK. However, the power supply in Norway is 220 v, and the K30 runs on 110 v.
I only use an adaptor, not a transformer.

Could this be the reason, or would the machine not even turn itself on?

zmz wrote:Could this be the reason, or would the machine not even turn itself on?

Yes and it only "turns on" once and then never again, not even on a 110V line anymore.

Meaning...?

Terranova wrote:Yes and it only "turns on" once and then never again, not even on a 110V line anymore.

Really?
So it couldn't simply be a blown fuse? Many electric machines have a small internal one. A 110V fuse would surely blow if 220V were applied over it.

zmz wrote:Meaning...?

Meaning you fried it.

zix wrote:Really?
So it couldn't simply be a blown fuse? Many electric machines have a small internal one. A 110V fuse would surely blow if 220V were applied over it.

Not necessarily. Fuses care about current, not voltage. Its entirely possible that the control electronics (which are very low power compared to a motor) died before the fuse blew, if the fuse blew at all (or if it even has a fuse). Its possible that a fuse blew, or that the control electronics have some sort of overvoltage protection, but its also possible that the electronics are fried. Something almost certainly got hurt. Don't fool around with plugging things into the wrong voltage unless you know exactly what you're doing.

Nate42 wrote:Not necessarily. Fuses care about current, not voltage.

Oh, but they do care about both. They are rated for a certain current at a certain voltage. And they come in slow or fast varieties.
Unless something on the inside limits the current, double the voltage at the same current means double the effect through that fuse, and this might very well blow the fuse. OK... If it is a slow-blow fuse it may not blow, of course.

A grinder without logic electronics, yes, I agree, you might suspect it may not have a fuse, but if there is a display there are electronics, and they usually are low voltage, and a fuse or two might be expected. At the very least, you could see if you can find any... It is not like it would hurt.

But the only way to find out, unless you already know that there is no fuse to be found, is to look for it, and I don't have a Mahlkönig K30 to look at.
OP: if you look at the bottom of the chassis (or wherever the mains lead enters the grinder) you may see a fuse symbol and a round little lid that you can unscrew with a coin. If you see this, pull the plug (unless you already did that) and unscrew the lid. If the fuse inside has blown, you can get a new one. Look at the rating and buy another one with the same rating.

And I second Nate42's advice: don't plug the grinder into 220V again. Not unless it clearly says on the grinder that it is made to run at both 220 and 110. Many consumer electronics power units can run on both nowadays, but I would guess that the K30 does not.

Fuses have a voltage rating for a safe operating limit (to avoid arcing) but its current (or rather the heat generated by power dissipation in the fuse due to that current) that actually makes the thing blow. As you say there are many different types of fuses, but I can certainly imagine a scenario where the logic board would be damaged and the input fuse be of no help. Unless we know the details of the design, its all speculation anyway. The logic board may have its own input protection, or it might not. Either way, driving it with over the rated voltage was a bad idea.