Nespresso Magimix M300 keep showing fill water. Tank is full, but it does not work.

Just a brief addition, I don't have the Magimix model, but I have a similar one. It loses it's programmed settings if it is unplugged or switched off at the wall, but if you leave it plugged in but turn it off with the switch at the back it keeps the settings you have put in. It draws virtually no power when it's switched off with the switch on the machine, (I checked it with a power meter).
Just thought I'd share that with you.

We had the same problem and were ready to return the device when we were able to fix it. Here is what we did:
1. Fill the water tank all of the way and place in machine
2. Let the tank sit in position for a few hours (we let ours sit for 3)
3. Run the descaling option
4. Run a few cycles of the "longo"
5. If the machine is still not working repeat the process (Ours started to run after the 2nd cycle)

It just appears that the pumps are shipping with air in them and needs patience to get it out. Once you get it going though you won't regret it :)

Check the magimix website...All the manuals are online...

cant get rid of scaled message

The manual can be found at the following location:
http://www.nespresso.com/precom/sav/pdf/User_manual_CLA.pdf

Call the Nespresso Club, they will hepl to solve it in no time
0800 442 442
Good luck
Frog

Try rescaling the machine.  The following is a PDF of the instructions:
http://www.nespresso.com/precom/sav/pdf/User_manual_CLA.pdf

it just means that the pump needs primed. Turn on at the wall and on the machine, wait until screen says ready (make sure water tank full), then turn steam handle on RHS to on (do not push the steam button). the pump will prime until water comes out of the steam nozzle. now turn off the steam handle and you are ready to go!

this has happened to me. try opening the steam wand (but without the steam function turned on) to force hot water out. that usually gets it going for me.

Sounds like it is deffective.  If it's under warranty (under 1 year old) Nespresso will pick it up at your residence and fix it/replace it for fre.