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Repair of a coffee grinder

Coffee is a useful and tasty drink that can give a feeling of cheerfulness. Some do not imagine the beginning of a day without him.
Although there are many varieties of instant coffee on the shelves, true connoisseurs of this drink, this product does not quite suit you. So, as the basic invigorating substance – caffeine, in it practically does not remain, after processing and an extract.
Therefore, in order to get a drink with better ingredients, it is necessary to have a coffee machine that is not quite available, or grind the fried grains in a coffee grinder and then prepare them in a turkey on the stove.
This option is not new and does not require a lot of money. Many left the Soviet coffee grinder, and in the stores of home appliances appeared imported, more practical devices for everyday use.
In modern coffee grinders, nothing has changed, in comparison with their domestic counterparts. The principle of operation remained the same, the only thing that was added was electronic control.
If we talk about the quality of products, it does not shine very much, so the device periodically needs repairs of varying complexity.
Here, in the photo there is a grinder with a problem in operation, that is, it does not react either to the connection to the network or to pressing the control buttons.


Repair of a coffee grinder

No short circuits, no smoke and no smoke from it. She just stopped working.

Let’s proceed to disassembly.

We put the device on its side and grasped the cursor of the regulator with your fingers, remove it.

Repair of a coffee grinder

Next, using a thin screwdriver, we remove the bottom from the latches.
It is supported by four latches and grooves in the casing.

Repair of a coffee grinder

In this coffee grinder there is a coil with a handle for rotation by means of which the wire for convenience “hides” inside the case. In this connection, the supply cable has rotating contacts on the bottom.

Repair of a coffee grinder

These contacts in the form of a block are removed together with the cable.

Repair of a coffee grinder

Then, unscrew the four screws securing the additional sole.
Withdrew it, you can see the engine itself, the electronic circuit and other necessary for the diagnosis of the details.

Repair of a coffee grinder

Just want to note the extreme inconvenience of inspection and diagnosis in general, as the wires are very short and thin, and everything is done compactly and concisely.

Repair of a coffee grinder

Basically, wires that go to the board and one wire from the motor interfere.

Repair of a coffee grinder

To continue the work, it is necessary to disconnect the wires from the board and this can be done without a soldering iron, since the connection is made on the connectors.
But to remove the fingers of these connections is not so easy, here will help a screwdriver with a straight tip.

Repair of a coffee grinder

Repair of a coffee grinder

In this way we do with the other compounds.

Repair of a coffee grinder

It would be nice to sketch or take pictures before removing the color of the wires, which one is located, so that during the subsequent connection it is not confused.
When the wires are removed, the electronic board can be pulled out of the housing and free access to the motor.

Repair of a coffee grinder

Repair of a coffee grinder

The motor can not be pulled out while the knife is fixed on its axis. It is wound counter-clockwise, as the carving is left. Therefore, unscrew the knife clockwise, and to fix the axis of the engine, insert the screwdriver into a special slot, as shown in the photo.

Repair of a coffee grinder

Repair of a coffee grinder

As soon as the knife is removed, the engine will easily come out of the enclosure to the outside.

Repair of a coffee grinder

Repair of a coffee grinder

Repair of a coffee grinder

Now we remove additional parts from the rotor, remembering the sequence of their installation.

Repair of a coffee grinder

Repair of a coffee grinder

Repair of a coffee grinder

Try to rotate the motor rotor with your fingers. If the rotation passes tight, it is necessary to disassemble the motor, wipe and lubricate the rubbing parts.

Repair of a coffee grinder

In our case, the rotor rotates freely, but additional lubrication does not interfere. You can do this without dismantling the motor.

Repair of a coffee grinder

We take on the tip of the screwdriver a lubricant, and we put it on the axle, next to the bearing. Next, move the axis of the rotor from top to bottom. Thus, part of the lubricant will get inside the bushing. This will give a better glide, which does not hurt, the more there is the opportunity to do it.
After that, check the length of the collector brushes. If they are short and practically fall out of the inserts, they should be replaced.
Next, we proceed to verify the integrity of the cord and the power connector.

Repair of a coffee grinder

To do this, detach it from the sole and plug the plug into the mains. Using a voltage indicator or an AC voltmeter, we measure the voltage across the contacts. How to do it, can be seen in the photo.

Repair of a coffee grinder

Repair of a coffee grinder

The pointer shows 220 volts, so the cord and connector are OK.
Now, we check the operation of the protection switch against accidental activation. During the operation of the coffee grinder, its closed lid presses against the glass rod, which in turn presses the switch and closes its contacts.
Therefore, connect the ends of the device to the terminals of the switch and press its button.

Repair of a coffee grinder

In normal operation, the instrument will show a short circuit. If it does not, then it’s in it, that is, replacement can not be avoided.
Now go to the engine check. We insert the board into special grooves, and the engine is placed side by side.

Repair of a coffee grinder

Also, insert the power connector with the cord in its place (in the bottom of the case) and plug the power plug into the network.
It is also necessary that the switch contacts at the time of verification are closed, you can do this by inserting the plastic rod, thus, as in the photo.

Repair of a coffee grinder

You can of course hold the button and finger at the time of starting, but it’s not entirely safe in the event of a short circuit in the motor winding.
To check now whether the voltage is coming to the motor and the board, connect one end of the pointer to the common wire and the other to the switch output.

Repair of a coffee grinder

The pointer should show the presence of voltage, as in the photo.
If there is no voltage, then the problem should be sought in the power connector of the sole.
Disconnect the mains plug from the mains.
When we checked the presence of voltage, and it is, connect the connectors to the corresponding contacts on the board.

Repair of a coffee grinder

The one that goes from the engine and to the board (common) is connected by a piece of copper wire, from the connector to the corresponding contact. It is necessary to do this so that the engine can be checked in a lying position, since it is more convenient and safer.

Repair of a coffee grinder

When the chain is assembled, we plug the power plug into the mains, and gently holding the engine, press the grinding degree selection button (one of three).
One of the LEDs on the control board should light. Next, press the start button.
The engine does not rotate, but when one of the connectors on the board moves, the rotation periodically appears and disappears.
It was exactly that connector where we connected the motor to the board, by means of a wire.
Subsequent testing of the circuit of this section showed that at the place where the plug was soldered, microcracks formed on the board and there was no good contact, respectively. The device did not show the circuit, from the plug to the place of its soldering on the board.

Repair of a coffee grinder

The problem was solved by soldering this place, and it is also advisable to dissolve the other two plugs using flux and tin.

Repair of a coffee grinder

Very good results are obtained from flux made from 30% ground rosin and 70% alcohol. It cleans the place of soldering well, and with its help the connection turns out to be sufficiently reliable.

Repair of a coffee grinder

Repair of a coffee grinder

Repair of a coffee grinder

When assembling, disconnect all the wires from the engine, we find and install a rubber gasket in its place. It should be installed exactly in the specified place.

Repair of a coffee grinder

Repair of a coffee grinder

Further, we put on a motor axis washers and a brass bushing.

Repair of a coffee grinder

Repair of a coffee grinder

Now, we try to insert the engine into the case of the coffee grinder without breaking the wires, and that its axis comes out into the hole of the working bowl.

Repair of a coffee grinder

Repair of a coffee grinder

When this happens, holding the engine with the right hand, screw the working knife counterclockwise.

Repair of a coffee grinder

Now the engine keeps on its axis from above, and from the bottom it should be fixed with a sole with a rubber gasket.
Before you put on the bottom, you need to connect all three connectors on the board. It is inconvenient to do this, but it is possible.
Also, we insert the START / STOP button and the glass caps of the operation mode indicator into the corresponding holes in the case.
After that, leveling the engine housing approximately under the seat of the gasket, – we put on the pallet.

Repair of a coffee grinder

The axis of the milling time adjustment resistor should be approximately in the center of the hole in the body of the machine.

Repair of a coffee grinder

Next, fix the lower part of the grinder body with a plastic sole.

Repair of a coffee grinder

We put the regulator on and turn on the coffee grinder and check the operation of the electronics. To do this, put on the cover or press the safety switch with your finger, and try to select the operating mode.

Repair of a coffee grinder

Repair of a coffee grinder

Repair of a coffee grinder

Different modes of operation should be highlighted by the corresponding LEDs.
After selecting the mode, press the “START” button.

Repair of a coffee grinder

The coffee grinder should work for a certain time and turn off on its own. The operating time depends on the degree of grinding. The larger it is, the less time it takes.
At this the repair is over and now you can again enjoy the taste of your favorite drink.

Repair of a coffee grinder


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