Do-it-yourself floor and table fan repair: diagnostics and troubleshooting

To repair a desktop or floor fan yourself at home, it is not necessary to be a master of the highest category, since often the cause of the malfunction lies in the little things that even a beginner can handle. Before you can remove the problem, you need to run diagnostics, which will reveal the problem.

Main problems

To identify the root cause of the malfunction, you need to find out what parts the fan consists of. Regardless of the type (floor or desktop), the device has exactly the same device. The difference is only in the length of the rack.

Problems in the operation of the fan are different, and each of them has its own causes and symptoms.

The fan does not turn on

The device may not turn on, but in this case it is important to pay attention to whether the light comes on or not when trying to start the device. If the indicator is on, but the device does not turn on, it means that the block with buttons, which is located on the fan rack, has broken.

If the light on the case does not turn on and the device does not make sounds, there may be no voltage in the outlet, or the reason lies in the breakage of the cord or plug. If it is impossible to start the household appliance and the above reasons are excluded, the problem should be sought in the electric motor.

Blades don’t spin well

The blades can rotate slowly for several reasons. The main one is the lack of lubricant in plain bearings. Sometimes the blades are deformed by high temperatures from the engine (when the device runs for too long, overheating occurs). In this case, the blades cling to the protective mesh, so finding such a problem is simple and quick.

The fan does not rotate sideways

If the fan device does not turn in different directions, or turns occur with a delay, you will have to disassemble the motor housing. Main reasons:

• loosening the screws on the crank;
• gear engagement in the gearbox;
• broken switch travel due to insufficient lubrication.

Cooler hums and does not rotate

Many people mistakenly call a fan a cooler, but in reality it is a cooling device that may not have blades. The main purpose of the cooler is to remove heated air from the fan. Sometimes it hums, but does not rotate. There are several reasons here:

• lack of lubricating oil in bearings;
• capacitor failure;
• engine malfunction.

The fan makes a lot of noise or whistles

A floor or table fan makes noise and whistle in such cases:

1. Deformation of the propeller, against the background of which there is an imbalance between the blades. In this case, the device also vibrates.
2. Loose bushing in plain bearing.
3. Indentation of the protective grid, for example, when falling.
4. Electric motor breakdown.
5. Instrument contamination.
6. The presence of a foreign object inside the system.

Other malfunctions

What else can happen with a floor and table fan:

1. Capacitor failure. Household fans usually use the dry type, which is made of plastic, which is easily deformed due to overheating.
2. Electrical motor failure. The main symptom is that the device does not start or produces unnatural sounds.
3. Malfunctions in the control unit. Most often, the reason lies in the worm gear and diffuser.
4. If there is a speed switch, then the fan may not work due to its malfunction. The reason is a break in the windings.
5. Rarely, a fan failure is in the rotor. This happens when the engine overheats.

Troubleshooting

Malfunctions of floor and table fans are of 2 types — mechanical and electrical. It is on the first that a simple layman does not pay much attention, and this leads to a breakdown in the electrical part of the device. For example, if the shaft is jammed, and the equipment continues to work, then this will undoubtedly cause the motor to overheat. If the bearing becomes loose, the stator winding will be damaged in the future.

Before diagnosing a fan at home, disconnect the device from the power supply. The unit often does not turn on due to a malfunction of the cord or outlet, therefore, first of all, any other device is connected to the power supply. If it does not turn on, then the culprit is the outlet that needs to be fixed.

To inspect the internal equipment of the fan, disassemble it, proceeding as follows:

1. Remove the main rim.
   
2. Unscrew the fasteners on the protective grid and remove its front part.
3. Disconnect the propeller with blades. Feature — in fans, the propeller is attached with a nut with a left-hand thread, which is screwed to the motor shaft. Therefore, the fasteners are unscrewed clockwise, and twisted vice versa.
   
4. Remove the protective mesh at the back by unscrewing the nut.
   
5. Loosen 4 screws.
   
6. Remove all mounting material from the motor housing and remove the panel. Do not forget about the bolt, which is located on the handle that regulates the rotation of the body. If this is not done, access to the engine will not open.
   
7. Remove the plug from the back of the instrument.
   
8. Loosen the screw.
   
9. The engine is open.
   

Since failure is often associated with a lack of lubrication, be sure to put a few drops of technical oil on the bushing.

Turn the shaft first in one direction, then in the other direction for better absorption of the lubricant. After that, assemble the fan in the opposite direction, turn on the device and check for operability.

More clearly about how to disassemble the fan and troubleshoot, see this video:

Mechanical failures

To detect malfunctions of the mechanical part of the fan device, pay attention to the following manifestations:

• extraneous sounds (noises, whistles, squeaks, etc.);
• slow speed of rotation of the blades during operation;
• difficulty turning the propeller when the fan is off.

Problems in the electrical part

An electrical malfunction is manifested by the following symptoms:

• the smell of burning;
• inability to start the unit;
• slowing down the speed of the propeller mechanism when the device is turned on;
• operation of automatic safety switches (if provided).

Do-it-yourself floor and table fan repair

After detecting a problem with the fan, you can proceed directly to the repair. First, prepare the necessary tools and materials, depending on the type of malfunction. The first thing that is checked after diagnosing the cord, plug and socket is the serviceability of the electric motor. Often the problem lies in the microcircuit, so first determine the level of current entering the board and output from the microcircuit. In the absence of voltage, the problem lies in the breakdown of the microcircuit, which can be replaced.

If the current goes to the microcircuit, but the floor or table fan does not turn on, you will have to disassemble the case and check if the current is flowing inside. If not, the problem is in the electric motor, so you will have to send the motor in for repair.

How to replace the chip:

• disconnect the two wires connecting the electrical plug and the microcircuit board;
• do the same with 2 wires going from the board to the motor;
• attach a new chip.

To understand how to repair a fan yourself, you need to know the principle of operation of the device. Scheme:

Peculiarities:

• asynchronous type motor, installed on standard floor and table fans, has 8 starting and working windings;
• to start, the phase is shifted by 90 degrees using a capacitor;
• start is carried out after pressing the power button (first the red indicator turns on, then the electric motor starts to rotate);
• the speed of the torque is affected by a 3-speed derailleur, which has mechanical interlocks for simultaneous speed shifting.

Rotor replacement

The rotor is usually located on a gasket under the cover or behind the shaft, so to repair or replace it, the motor is removed with screwdrivers. The first thing to do is to inspect the wiring, which may be causing the problem. If no defects are found on it, you will have to change the rotor, since it is not possible to repair it yourself. Be sure to write down the device number and purchase the exact same model.

How to replace the rotor:

• carefully disconnect the wire leading to the rotor;
• unscrew the screws;
• remove the device;
• fit the new rotor, screwing firmly to the base.

How to fix the control unit?

The control unit breaks due to the worm gear. You can fix this problem yourself by following the instructions:

• remove the terminal block (the motor does not need to be removed);
• if there are gaskets for the control unit, remove them;
• unscrew the shaft with a screwdriver;
• remove the control unit;
• dismantle the cover at the back, opening access to the worm gear;
• to check the performance, use a tester (without breakage, the resistance parameters should not exceed 50 ohms);
• in case of violations, replace the old element with a new one.

What to do if the flange is broken?

Floor and table fans use plastic flanges that break easily, especially if the unit is dropped. Therefore, a replacement is required. How to do it:

• unscrew the back cover near the motor or shaft, depending on the model;
• remove the crank;
• disconnect the worm gear without removing the control unit;
• remove the switch;
• unscrew the screws from the flange and disconnect it;
• install the new flange in reverse order.

Diffuser repair

The diffuser is located in the control box. The cause of its failure is the twisting of the regulator. Change it like this:

• remove the top cover without touching the engine;
• disconnect the center flange;
• remove the control unit;
• remove the diffuser from the back (pry off the base with a screwdriver or knife);
• replace with a new element.

cooler repair

If the part with the propeller and blades is broken, use the following tips:

1. In case of normal deformation of the impeller due to overheating, it is necessary to remove the propeller, warm the blades slightly and align them so that they do not touch the fan protective mesh.
2. If the blades break, you will have to buy a new propeller and install it yourself.
3. If a small part of the cooler is torn off, the fragments can be glued together with reliable glue.

How to repair a capacitor?

The capacitor usually breaks down due to sudden power surges in the electrical network. The part is located behind the central flange. The cause of the malfunction is the lack of phase shift or winding power supply. The main symptom is no rotation. The failure of the capacitor is checked with a multimeter (measurement mode — resistance).

Before measuring, discharge the device to a minimum (just short the leads together). After contact with the probes, follow the readings:

• serviceability of the capacitor — short-term readings and breakage;
• malfunction — equality of readings 0 or infinity, their invariance.

When buying a new device, pay attention to the voltage and capacitance of both capacitors — they must be equivalent. How to replace:

• remove the motor from the housing;
• disassemble the power supply;
• if the crank interferes, remove it and the flange (depending on the model);
• disconnect the capacitor, install a new one.

How to repair the speed switch?

If the speeds do not switch, look for the problem directly in the switch. To do this, do the following:

• unscrew the back cover;
• remove the contact block;
• inspect the regulator.

The most common causes and methods for their correction:

• disconnecting the conductor — just solder it back;
• speed switch burnt out — replace with a new part.

Bearings

In household fans put plain bearings mounted on a rotation shaft with bushings. It is impossible to get these devices, as they are pressed into the body at the factory. Separate parts are not sold, so you have to replace the entire unit. To avoid this, often drip machine oil into the bearings.

The fact is that during “dry” operation a gap is formed between the bearing part and the shaft, due to which axial runout occurs, the number of revolutions decreases, and wear of parts accelerates. Bearings also become dirty, so be sure to clean them before lubricating.

Crank

The crank may be deformed or fly out. In the second case, the shaft is the culprit. To get rid of the problem, do the following:

• remove covers;
• remove the stator;
• unscrew the shaft;
• take out the crank;
• reinstall carefully.

If stainless cranks are deformed, use a vise to straighten or take the part to a workshop.

Lamps and buttons

If the indicator light does not light up, it is burned out. Therefore, it is replaced with a new one, for which the structure is dismantled. But it also happens that the lamp is lit in red, and the fan does not work. In this case, the button block is the culprit — the buttons do not work. Their work is quite simple — the transition from the «on» to «off» position.

To check the performance, a tester is used, which checks the input and output of the button block. If one of the switches is broken, you will have to change the entire unit.

The fan does not turn sideways

The reasons for such a breakdown are mentioned above, but troubleshoot in the following way:

1. If the fasteners on the crank are loose, disassemble the motor housing by removing the rear cover. Next, under the gearbox, the degree of connection of the gear and crank is checked. Secure with tools if necessary.
2. If the gears fail, you will have to disassemble the gearbox and remove the gear. Perhaps it clings due to wear or lack of lubrication. If worn, replace the part.
3. When the elements are dry, lubricate all moving parts with oil.

Problems due to imbalance of the impeller

After repairing a floor or table fan, the propeller must be installed correctly. Otherwise, the blades will not rotate normally. Usually, a simplified method is used — static balancing. How to do it:

• put the fan in operating mode;
• manually set the initial rotation;
• mark the top point of the blades with a pencil;
• do some rotations.

These manipulations allow you to identify imbalances. If the impeller has not returned to its starting point, the bearings are lubricated; if the points match, make a counterweight. For this, any materials at hand are used — nuts, screws, wire, etc. The load is fastened to the propeller using electrical tape, adhesive tape, glue. In order to lose the permanent place of the overweight point, the load is mounted to it, but from the inside of the blade.

Do-it-yourself fan repair (video)

You can see clearly how a floor or table fan is repaired in the following video:

Helpful Tips

Pay attention to the following helpful tips:

• do not let the fan run for too long (continuously);
• do not use fan equipment with open rotating elements, that is, in the absence of a protective grille;
• do not allow direct sunlight on plastic elements (they are deformed);
• do not forget about lubrication;
• do not install the device near heating appliances (gas or electric stove);
• if you doubt that you will remember the exact location of all the details, it is better to take appropriate photographs during disassembly of the fan;
• do not turn on the device directly to the mains after self-repair — use RCD blockers (if they work, take the fan to the workshop or recheck the wire connection).

If you started repairing a floor or table fan with your own hands, be sure to study all the information, and if necessary, consult with specialists. Even if you do not have enough experience, still try and believe in yourself.