Nivona Caferomatica 770 Grindstone replacement

Introduction

The grinder is the same as in many devices from Jura, Siemens, Bosch, Melitta, etc... The pictures of the grinder are therefore from a Jura, but the repair is basically the same.

What you need

Step 1 Nivona Caferomatica 770 opening

Nivona Caferomatica 770 Grindstone replacement, Nivona Caferomatica 770 opening: step 1, image 1 of 1

Pull the power plug!
Remove all attachments such as water reservoir, coffee compartment lid, trestle drawer. Remove all coffee beans in the storage container.
Unscrew the five Torx T10 screws on the back.

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Step 2

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Unscrew the two Torx T10 screws on the front edge of the heat plate.
Do not remove the heat plate completely yet, its supply cables are still connected.
Lift the front edge of the heat plate and slide it forward a bit to clear the tabs on the back edge.
Put the heat plate back down, but in such a way that you can reach the screws underneath.
Unscrew the two Torx T10 screws located under the heat plate.

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Step 3

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Gently lift the upper side a bit and put it back down.
Push the side panel on the water tank back about 2 cm.
This may jam a bit.
Place the side panel next to the machine. Do not remove it completely yet, the cables of the switch are still connected.
Disconnect the flat plugs from the switch. Be sure to note the order of the cables for later reassembly.
Remove the side panel.

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Step 4

Loosen the two insulated flat plugs with which the heat plate is connected.
Lift the top slightly upwards and loosen the nut that secures the eyelet to the green-yellow grounding cable. Remove the eyelet.
Do not remove the top yet, it is still connected with a sensor cable.

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Step 5

Lift the top side slightly.
Press down the locking tab on the plug of the white sensor cable and pull off the black plug towards the front of the machine.
Press the two catches of the counterpart on the sides together and slide it out of the opening towards the back.
Now the top is free and you can remove it.

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Step 6

Slide the side panel with the service door back about 2 cm and remove it.
This may jam a little.

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Step 7 Nivona Caferomatica 770 Grinder opening

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Nivona Caferomatica 770 Grindstone replacement, Nivona Caferomatica 770 Grinder opening: step 7, image 2 of 2

The grinder is damped with foam mats. One mat just rests on top. Remove it.
Work carefully, the mats tear easily.
The grinder is open in front of you.

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Step 8 Removing The Grinder Ring

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Now the grinder is free. Again take a picture, then pull out the axis of the adjuster with moderate force.
This adjuster may not be present on some models.
Depending on the model you will find a silicon sealing on top of the grinder ring, remove it.
Watch the fabrication signs , here green. This alignment must be restored later. Now turn the great black gear about 90 degrees counterclockwise. The grinder ring is free and can be lifted off.

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Step 9 The Grinder Cone

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In the next step be very careful not to loose these three springs, balls and cartridges.
The grinding cone is fastened with a long Torx T20 screw. The screw head is often covered with remnants of coffee beans. Expose the head and turn the screw out counterclockwise.
Now the bean feeder (the small white snail) can be removed. The grinder cone and drive can now also be lifted up carefully.

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Step 10 Cleaning

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Nivona Caferomatica 770 Grindstone replacement, Cleaning: step 10, image 2 of 2

The grinder is usually filled with old, sticky coffee grounds. Clean everything carefully for an excellent coffee aroma.
Gently lift the felt ring around the drive shaft with a needle, then wipe it clean with a damp cloth. Do not attempt to wash it, as there is a risk that it will swell. When first used, turn it over with the clean side up.
Clean the inside of the grinder with a brush and damp cloth, and the blades with a dishwashing brush. Ensure it is properly dried before use.

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Step 11 Change The Grinder Ring

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Push both of the small latches alternately. Then the ring cover should come out.
Two clamps hold the grinder ring in its place, push them aside and it should come free.
Again clean everything. Press the new ring and cover in its place. With that the grinder ring is exchanged.

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Step 12 Change The Grinder Cone

Nivona Caferomatica 770 Grindstone replacement, Change The Grinder Cone: step 12, image 1 of 1

First insert the cleaned driver, then the three sleeves, springs and balls. Now fit the grinding cone on the three balls.
Then fit the auger, screw in central screws. When screwing in, push the cone downwards and make sure that everything meshes.
This screw turns into plastic. If it doesn't fit properly, the thread will be damaged. So first turn the screw counterclockwise until you feel that the first thread is engaged. Then tighten it turning clockwise.

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Step 13 Reassembling

Nivona Caferomatica 770 Grindstone replacement, Reassembling: step 13, image 1 of 1

Insert grinding ring. The black gear is turned to the right again until the three marks are aligned. Then reinstall the adjuster drive shaft as it was originally.
The adjustment oft the new grinder burrs musst not necessarily be the same as the old ones. You can approximately find the mean position, which was marked before, by turning the outer ring as far as possible clockwise, then turning it fourteen clicks backwards.
It is a good idea to check if the grinder rotates freely. You can remove the meal hopper and look at the millstones from the side.
Then install the remaining parts in reverse order.
You can set the grinding degree nicely by placing an empty roll of toilet paper perpendicular to the open mill and filling it with a few coffee beans. Plug in the plug (be careful!), choose a cup of coffee and watch as the coffee grounds fall out of the grinder.

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Step 14 Before - After

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Nivona Caferomatica 770 Grindstone replacement, Before - After: step 14, image 2 of 2

These two pictures are no fake: Before repairing the grinder the coffee is thin and transparent. With new stones the coffee is strong and has a fine crema. The repair was a real success!

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