How to Repair Small Appliances_Blender

How to Repair a Blender

A food blender is a popular and useful kitchen appliance. Foods and liquids placed in it are blended or chopped based on the speed set by the operator. Today's food blender can chop ice, make peanut butter, grate cheese, and perform many other useful functions.

How Food Blenders Work

The kitchen food blender is a motorized small appliance. A blade inside a jar is connected to a motor shaft. By varying current to the motor, the blade's speed is controlled.

Preventive maintenance can reduce the repairs needed to keep a food blender running for many years. The two most important steps an operator can take are not to overload the blender and to keep the seals tight.

©2006 Publications International, Ltd. The cross section of a blender.

The multispeed switch in the blender sends current to the motor based on which control buttons are selected or how far the rheostat is turned. More current means a higher motor speed. Placing hard foods in the blender jar and trying to chop them with a low motor speed can cause the motor to burn out.

Because the jar holds liquids, yet must be disassembled for cleaning, it has seals to keep liquids from escaping. In addition, the blender housing has a seal around the coupling to make sure liquids don't leak into the vulnerable motor. Keeping these seals tight and ensuring that liquids don't overflow the jar can help keep a blender operating smoothly.

How to Repair a Food Blender

Food blender repairs include servicing a multispeed switch, replacing a fuse, servicing a motor, tightening a drive stud, and servicing a blade assembly.

Servicing the Multispeed Switch: It's easy to see why the multispeed switch is a critical component to the operation of your food blender. Because of its high use and complexity, it is a frequent culprit when things go wrong. To service the multispeed switch:

Step 1: Remove the blender base.

Step 2: The multispeed switch will be attached to the base with clips or screws accessed from underneath the base's faceplate or from inside the base. Visually inspect the switch before removing it; in many cases, the problem is a loose terminal. Otherwise, a blackened terminal or wire may identify where the problem has occurred.

Step 3: Check the multispeed switch with a continuity tester or multitester.

©2006 Publications International, Ltd. Remove a blender's multispeed switch and test it.

Step 4: Because of its exposed location on the front of the blender, the switch is susceptible to damage from liquids. Use a can of compressed air or an electrical contact cleaner to clean the switch. If necessary, replace it.

Replacing the Fuse: Fortunately, most blenders include an in-line fuse that protects the motor from overload. If excessive current is sent to the motor, the fuse will blow. To determine if the fuse is working:

Step 1: Remove the blender base and locate the fuse in the wire from the multispeed switch to the motor.

Step 2: Disconnect the wire and use a continuity tester or multitester to check the fuse. If the circuit is open, the fuse is blown.

Step 3: Replace the faulty in-line fuse with one of identical rating.

Servicing the Motor: The motor will typically withstand many years of use (though not much abuse). Unfortunately, if the motor needs to be replaced, it may be less expensive to buy a new blender.

Troubleshooting  Food BlendersCan't figure out what's wrong with your blender? Click herefor a troubleshooting chart that just might solve the problem.

Motor operation is easy to test. Because there is a circuit running from the appliance cord, through the multispeed controls, to the motor, and back to the cord, an ohmmeter (part of your multitester) can test the circuit. To test a blender's motor:

Step 1: Place a probe on each cord prong.

Step 2: Select a speed-control button or turn the speed controller slightly, then read the resistance on the meter.

Step 3: Next, rotate the drive stud clockwise one turn. If the resistance reading (in ohms) changes, the motor needs service. Take it to an appliance-repair service or replace the appliance, depending on cost.

Tightening the Drive Stud: If the motor operates well, but the blade in the blender jar doesn't turn as it should, the problem may be the drive stud. The most frequent cause is a loose drive stud. To tighten the drive stud:

Step 1: Remove the base and turn the blender over. The other end of the drive shaft will protrude from the bottom side of the motor.

Step 2: Grip the drive shaft with a wrench or pliers, then turn the blender on its side to attach a wrench to the drive stud.

Step 3: Hold the drive shaft steady as you turn the drive stud clockwise.

The other cause of drive stud problems is the rounding of its corners, requiring a new drive stud. To replace a worn drive stud, reverse the instructions for tightening a drive stud, install the new part, and tighten it.

Service the Blade Assembly: The blender's blade assembly is simple in function. It is rotated by the drive stud, which blends or chops food within the jar.

©2006 Publications International, Ltd. A blender's blade assembly blends or chops food in the jar.

The most common problem is caused by the jar leaking liquids. The solution is to tighten the base. If this doesn't solve the problem, inspect and, if necessary, replace the gasket.

If the drive stud is turning but the blade assembly isn't, inspect the assembly socket into which the drive stud fits. It may be worn and require replacement. This is a common problem on blenders with metal drive studs and plastic blade-assembly sockets.

It's time to open up and talk about how to repair electric can openers. See the next page for suggestions.

Source : http://home.howstuffworks.com/how-to-repair-small-appliances5.htm

How to Repair Small Appliances

Electricity furnishes the energy that powers small appliances and other electrical devices. Current flows to the device through the hot (typically black) wire and returns through the neutral (typically white) wire. The power that moves the current is called voltage.

In most household systems, the hot wire has about 120 volts and the white wire has zero volts. The difference in voltage between the two wires moves the electric current and powers your appliance.

There are three types of small, portable, or household appliances. Some appliances, such as toasters and coffee makers, heat something. Other appliances, like food processors and vacuum cleaners, move something. A few appliances, such as hair dryers, do both.

In this article, we'll tell you how to repair all of these appliances, and more. First, though, we'll provide an overview on fixing small appliances.

Heating Appliances

Heating appliances convert electrical energy into heat, which is used to toast bread, warm coffee, dry hair, or perform other helpful tasks. This heat is developed by passing current through a special wire called an element. Since the element makes it difficult for electricity to pass through it, some of its energy turns into heat. The electricity uses so much of its energy to overcome the resistance of a toaster element, for instance, that it glows bright red, thus toasting the bread.

Common heating appliances covered in this article include toasters, toaster ovens, drip coffee makers, and percolator coffee makers. Heating appliances that work on the same principles include clothing irons; electric fry pans, woks, griddles, and waffle irons; convection ovens; deep fryers; slow cookers; food dehydrators; rice cookers; steam cookers; indoor grills; espresso and cappuccino machines; iced tea makers; and popcorn poppers. Once you've learned how to troubleshoot and repair the most popular heating appliances, it will be easy to repair any of them.

Motor Appliances

©2006 Publications International, Ltd. Circuits for heating and motor appliances.

Motor appliances convert electrical energy into movement. This power cuts and blends foods, opens cans, grinds waste, picks up dirt, and moves air. A motor converts electrical energy into magnetic energy that rotates a shaft. The end of this shaft may have a blade or other attachment that does the actual work.

Motor appliances that are addressed in this article include food mixers and blenders, electric can openers, garbage disposers, and upright and canister vacuum cleaners. Other motor appliances with similar operation include juicers, coffee grinders, ice cream makers, electric knives, knife sharpeners, electric pencil sharpeners, electric clocks, fans, humidifiers, and foil-head and rotary-head electric shavers.

Combination Appliances

Some small appliances both heat and move. The most popular is the electric bread maker. It mixes dough, then bakes it into bread. Bread makers also include diagnostic electronics that assist the owner in troubleshooting and repair, so they are not included in this article. Other combination appliances include hair dryers and stirring popcorn poppers.

Troubleshooting Small Appliances

Nearly all small appliances are powered by 120-volt electricity. This means that many of the problems that can occur with toasters can also occur with garbage disposers and hair dryers. These problems are caused by circuit breakers or fuses, switches and plugs, or grounded or loose wires.

In this article, you'll learn how to easily solve many common problems with small appliances, beginning with repairing cords.

Appliance Cords

An appliance cord delivers electricity to an appliance. An appliance cord is typically constructed of two or three wires and a plug. Attach the appliance end of the cord with metal connectors or fasteners like electrical nuts.

©2006 Publications International, Ltd. A typical appliance cord connection. See more  pictures of small appliances.

Wires

Wires used in appliance cords are of different diameters, or gauges. The thicker the wire, the lower the gauge number. That is, a 12-gauge wire is thinner than a 10-gauge wire. Most small appliances use cord wires of copper strands insulated with heat-resistant plastic.

An appliance that requires less amperage to operate, such as a lamp, will typically have a two-wire cord of 18- or 16-gauge wire. Higher-amperage heating appliances will use a two- or three-wire cord of 14- or even 12-gauge wire. Two-strand cords include one hot wire and one neutral wire. A three-strand cord will have one hot wire, one neutral wire, and one ground wire.

Plugs

The plug at the end of an appliance cord receives electricity from the wall receptacle. A two-prong plug is typically used for ungrounded appliances rated at less than 15 amps. Some two-prong plugs are polarized to ensure that the hot and neutral wires are connected correctly. The smaller prong is the hot wire, and the larger one is neutral.

Three-prong appliance plugs include one round prong used for grounding and ensuring that the hot and neutral prongs are inserted into the correct receptacle slots. Most small appliances are rated at less than 15 amps. A receptacle with a T-shaped neutral slot is designed to accommodate 20-amp appliances, though 15-amp cords can be plugged into it.

Connectors

At the other end of the cord, inside the small appliance, the wires are connected to a switch, or controller. The wires may be connected with solder, with electrical twist-on nuts, or with connectors. These connectors physically and electrically connect the power source with the appliance.

The connection can be made with crimp connectors, clip or spade connectors, or with U- or O-connectors. Internal appliance wires are typically smaller than those used for cords, which means the gauge numbers are higher.

Repairing Appliance Cords and Wires

To test an appliance cord or wire, first make sure that it is disconnected from any electrical source or capacitor. Then use a continuity tester or multimeter to make sure it can adequately conduct electricity.

With the tester attached, move the wire to ensure that there is not a break in the strands that can cause intermittent shorts. Also check the quality and pliability of the cord or wire insulation. If there are any breaks or cracks that may eventually expose strands, replace the cord or wire with one of equivalent rating and gauge.

Small Appliance Controls

Electrical power coming into a small appliance must be controlled: turned on or off or varied based on temperature, time, or function. That's what appliance controls do. Appliance controls include switches, thermostats, rheostats, and timing mechanisms.

In many small appliance problems, a controller is the culprit. So, before you begin tearing your toaster or vacuum apart, let's see how small appliance controls work -- and what to do when they don't.

Switches

Most small appliance switches are activated by hand to control the flow of current in an appliance. A single-pole switch is pushed or moved to turn power on or off. Multiposition switches allow set amounts of current to flow, such as a multispeed switch for a blender.

©2006 Publications International, Ltd. Appliance controls include thermostats, rheostats,  timing mechanisms, and assorted switches.

Thermostats

A thermostat opens and closes a circuit to furnish current based on temperature. The simplest, a bimetallic thermostat, uses two bonded pieces of metal with different heat ratings. At room temperature, for example, both metals are of identical length and form, allowing contact points in the circuit to touch. Heat flexes one of the two metals and causes them to pull the contacts apart, opening the circuit and stopping current from passing. 

Thermostats can be used to turn a heating element or a motor on or off. In fact, thermostats are used as overload protectors that open a circuit and turn off a motor if it overheats or overloads.

Rheostats

A rheostat is a variable controller. That is, it variably controls the amount of current flowing to an appliance component. A blender with a speed control that can be turned to increase or decrease motor speed uses a rheostat to do so. Because rheostats can be damaged by moisture, they can easily malfunction. In that case, they must be replaced with a rheostat of the same type and function. Rheostats are also called potentiometers or "pots."

Timing Mechanisms

A timing mechanism controls current flow based on a mechanical or digital timing device similar to a clock. A timing mechanism in your coffee maker can furnish fresh coffee in the morning. In most cases, timing mechanisms turn small appliances on or off. When a timed appliance doesn't turn on, one of the first components to check is the timing mechanism. Some can be repaired, while others must be replaced.

Repairing Appliance Controls

Appliance controls are easily tested with a continuity tester. By placing the clip on the input side and the tester probe on the output side and activating the controller, you can 
determine whether the control is functioning properly. For variable controllers, it may be easier to use a multimeter that will show you a change in resistance. 

Most defective small appliance controls should be replaced rather than repaired. Once you remove the controller from the appliance, take the part, along with the appliance's model and serial numbers, to an appliance-parts dealer or electronics store to ensure that the appropriate replacement is found. A switch with a higher amp rating or a rheostat with a higher ohm rating can damage your appliance's heating element or motor. It can also be dangerous to the operator.

Where can you find replacement parts for small appliances? First, check your owner's manual to identify the model and part numbers. If you live in or near a metropolitan area, you may have a number of appliance-parts stores from which to purchase. Of course, call them first to determine if they have or can get the type of parts you require. Then take the defective part in for a side-by-side comparison with the replacement part to double-check the match before you purchase it. As a last resort, you can write to the manufacturer. In most cases, they will refer you to an area appliance-parts dealer.

Since most small appliances are made up of similar parts, it's pretty easy to troubleshoot any problem once you have the basics down. However, there are specific tips for each small appliance that may come in handy. Let's start by taking a look at how to repair toasters.

Source : http://home.howstuffworks.com/how-to-repair-small-appliances.htm