Notes on the Troubleshooting and Repair of Small Household Appliances and Power Tools


[Document Version: 2.08] [Last Updated: 05/25/1998]

Chapter 1) About the Author & Copyright

Notes on the Troubleshooting and Repair of Small Household Appliances and Power Tools

Author: Samuel M. Goldwasser
Corrections/suggestions: | Email

Copyright (c) 1994, 1995, 1996, 1997, 1998
All Rights Reserved

Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied:

  1. This notice is included in its entirety at the beginning.
  2. There is no charge except to cover the costs of copying.

Chapter 2) Introduction

  2.1) Where do you keep your dead appliances?

If you have ever tried to get a small household appliance or portable power
tool repaired, you understand why all that stuff is likely to be gathering
dust in your attic or basement closet or junk box.  It does not pay!  This
may be partially by design.  However, to be fair, it may take just as much
time to diagnose and repair a problem with a $20 toaster as a $300 VCR and
time is money for a repair shop.  It is often not even economical to repair
the more expensive equipment let alone a $40 electric heater.  The cost
of the estimate alone would probably buy at least one new unit and possibly
many more.

However, if you can do the repair yourself, the equation changes dramatically
as your parts costs will be 1/2 to 1/4 of what a professional will charge
and of course your time is free.  The educational aspects may also be
appealing.  You will learn a lot in the process.  Many problems can be
solved quickly and inexpensively.  Fixing an old vacuum cleaner to keep
in the rec room may just make sense after all.

This document provides maintenance and repair information for a large number
of small household appliances and portable power tools.  The repair of
consumer electronic equipment is dealt with by other documents in the
"Notes on the Troubleshooting and Repair of..." series.  Suggestions for
additions (and, of course, correction) are always welcome.

You will be able to diagnose problems and in most cases, correct them as
well.  Most problems with household appliances are either mechanical (e.g.,
dirt, lack of or gummed up lubrication, deteriorated rubber parts, broken
doohickies) or obvious electrical (e.g., broken or corroded connections,
short circuits, faulty heating elements) in nature.  With minor exceptions,
specific manufacturers and models will not be covered as there are so many
variations that such a treatment would require a huge and very detailed text.
Rather, the most common problems will be addressed and enough basic principles
of operation will be provided to enable you to narrow the problem down and
likely determine a course of action for repair.  In many cases, you will
be able to do what is required for a fraction of the cost that would be
charged by a repair center - or - be able to revive something that would
otherwise have gone into the dumpster - or remained in that closet until
you moved out of your house (or longer)!

Since so many appliances are variations on a theme - heating, blowing,
sucking, rotating, etc. - it is likely that even if your exact device does
not have a section here, a very similar one does.  Furthermore, with your
understanding of the basic principles of operation, you should be able to
identify what is common and utilize info in other sections to complete a

Should you still not be able to find a solution, you will have learned a great
deal and be able to ask appropriate questions and supply relevant information
if you decide to post to sci.electronics.repair (recommended), alt.home.repair,
or misc.consumers.house.  It will also be easier to do further research using
a repair textbook.  In any case, you will have the satisfaction of knowing you
did as much as you could before finally giving up or (if it is worthwhile
cost-wise) taking it in for professional repair.  With your newly gathered
knowledge, you will have the upper hand and will not easily be snowed by a
dishonest or incompetent technician.

Chapter 3) Some Tidbits

You may not realize the following:

* Virtually any table lamp can be restored to a like-new condition
  electrically for less than $5 in parts.

* The cause of a vacuum cleaner that starts blowing instead of sucking
  is likely a dirt clog somewhere.  It is virtually impossible for the
  motor to spin in the wrong direction and even if it did, the vacuum
  would still have some suction due to the type of blower that is commonly

* Many diagnoses of burned out motors are incorrect.  Very often motor
  problems are actually something else - and minor.  A truly burned out
  motor will often have died spectacularly and under adverse conditions.
  It will likely be smelly, charred, or may have created lots of sparks,
  tripped a circuit breaker or blew a fuse.  A motor that just stopped
  working may be due to worn (carbon) brushes, dirt, or a fault elsewhere
  in the appliance like a bad connection or switch or circuit - or the AC
  outlet might be bad.

* Fluorescent lamps use only 1/3 to 1/2 of the power of an incandescent lamp
  of similar light output.  With all the lighting used in an average household,
  this can add up particularly for high power ceiling fixtures.  However,
  fluorescent light color and quality may not be as aesthetically pleasing
  and fixtures or lamps may produce Radio Frequency Interference (RFI) causing
  problems with TV or radio reception.  Dimmers can usually not be used
  unless they are specifically designed for fluorescent fixtures.  Compact
  fluorescent lamps do indeed save energy but they can break just like any
  other light bulb!

* The initial inrush current to an incandescent bulb may be 10 times the
  operating current.  This is hard on switches and dimmers and is part of
  the reason behind why bulbs tend to burn out when switched on and not
  while just sitting there providing illumination.  Furthermore, an erratic
  switch or loose connection can shorten the life of an incandescent bulb
  due to repeated thermal shock.  And, these are not due to short circuits
  but bad intermittent connections.  True short circuits are less common
  and should result in a blown fuse or tripped circuit breaker.

* Bulb Savers and other devices claiming to extend the life of incandescent
  light bulbs may work but do so mostly by reducing power to the bulb at the
  expense of some decrease in light output and reduced efficiency.  It is
  estimated that soft start alone (without the usual associated reduction in
  power) does not prolong the life of a typical bulb by more than a few hours.

  Thus, in the end, these device increase costs if you need to use more or
  larger bulbs to make up for the reduced light output.  The major life cycle
  expense for incandescent lighting is not the cost of the bulbs but the cost
  of the electricity - by a factor of 25 to 50!  For example, it costs about
  $10 in electricity to run a 100 W bulb costing 25 cents over the course of
  its 1000 hour life.  However, these devices (or the use of 130 V bulbs) may
  make sense for use in hard-to-reach locations.  Better yet, consider compact
  or normal fluorescent bulbs or fixtures which last much longer and are much
  more efficient than incandescents (including halogen).

* Smart bulbs are legitimate technology with built in automatic off, dimmers,
  blink capability, and other 'wizzy' features but they burn out and break just
  like ordinary bulbs.  Thus, it hardly makes sense to spend $5 to $10 for
  something that will last 1000 to 1500 hours.  Install a proper dimmer,
  automatic switch, or external blinker instead.

* A Ground Fault Circuit Interrupter (GFCI) protects people against shock
  but does not necessarily protect appliances from damage due to electrical
  faults.  This is the function of fuses, circuit breakers, and thermal
  protectors. A GFCI *can* generally be installed in place of a 2-wire
  ungrounded outlet to protect it and any outlets downstream.  Check your
  local electrical Code to be sure if this is permitted.

* Don't waste your money on products like the 'Green Plug', magnetic water
  softeners, whole house TV antennas that plug into the wall socket, and
  other items of the "it sounds too good to be true' variety.  These are very
  effective only at transferring money out of your wallet but rarely work as

  - The Green Plug will not achieve anywhere near the claimed savings and may
    actually damage or destroy certain types of appliances like, guess what?:
    refrigerators and other induction motor loads.  Ever seen the demo?

    The Green Plug is supposed to reduce reactive power (V and I out of phase
    due to inductive or capacitive loads) but residential users don't pay for
    reactive power anyway, only the real power they use.  In addition, this is
    a minor concern for modern appliances.

    The demo you see in the store that shows a utility meter slowing down
    substantially when the Green Plug is put in the circuit is bogus for two
    reasons: (1) The motor being powered is totally unloaded resulting in a
    high ratio of reactive to real power.  Under normal use with a motor
    driving a load, the reduction in electricity use would be negligible.
    (2) The meter is wired to include reactive power in its measurement which,
    as noted above, is not the case with residential customers.

  - Magnetic and radio frequency water softeners are scams - pure and simple.
    They cloak absolutely useless technology in so much 'technobabble' that
    even Ph.D. scientists and engineers have trouble sorting it all out.
    The latest wrinkle adds advanced microprocessor control optimized for
    each potential mineral deposit.  Yeh, sure.

    Mention the word 'magnetism' and somehow, people will pay $300 for $2
    worth of magnets that do nothing - and then be utterly convinced of their
    effectiveness.  They forget that perhaps the instruction manual suggested
    changes in their water use habits - which was the true reason for any
    improvement.  Perhaps the magnets can be used to stick papers on the
    refrigerator once you discover they don't do anything for the water.

    BTW, the same goes for magnetic wine flavor enhancers :-).

  - Whole house TV antennas are great for picking up signals with ghosts,
    noise, and other distorting effects.  The premise that 'more is better'
    is fundamentally flawed when it comes to TV reception.  In rare cases
    they may produce a marginally viewable picture in an otherwise unfavorable
    location but these are the exceptions.  A pair of set-top rabbit ears will
    generally be superior.

  I will be happy to revise these comments if someone can provide the results
  of evaluations of any of these devices conducted by a recognized independent
  testing laboratory.  However, I won't hold my breath waiting.

Chapter 4) Basic Appliance Theory

  4.1) What is inside an appliance?

There isn't much rocket science in the typical small appliance (though that
is changing to some extent with the use of microcomputer and fuzzy logic
control).  Everything represents variations on a relatively small number
of basic themes:

* Heating - a resistance element similar to what you can see inside a
  toaster provides heat to air, liquids, or solids by convections,
  conduction, or direct radiant (IR) heat.

* Rotation, blowing, sucking - a motor provides power to move air as in
  a fan or vacuum cleaner, water as in a sump pump, or provide drive as
  in an electric pencil sharpener, food mixer, or floor polisher.

* Control - switches and selectors, thermostats and speed regulators,
  and microcomputers determine what happens, when, how much, and assure
  safe operation.

  4.2) Basic electrical principles

Relax! This is not going to be a tutorial on computer design.  Appliances
are simple devices.  It is possible to repair many appliance faults without
any knowledge beyond 'a broken wire is probably a problem' or 'this part
is probably bad because it is charred and broken in half'.  However, a
very basic understanding of electrical principles will enable you to more
fully understand what you are doing.  Don't worry, there will be no heavy
math.  The most complicated equations will be variations on Ohm's law:
V=I*R and P=V*V/R.

  4.3) Voltage, current, and resistance

If you have any sort of background in electricity or electronics, then
you can probably skip the following introductory description - or have
some laughs at my expense.

The easiest way to explain basic electrical theory without serious math
is with a hydraulic analogy.  This is of the plumbing system in your house:

Water is supplied by a pipe in the street from the municipal water company
or by a ground water pump.  The water has a certain pressure trying to
push it through your pipes.  With electric circuits, voltage is the analog
to pressure.  Current is analogous to flow rate.  Resistance is analogous
the difficulty in overcoming narrow or obstructed pipes or partially open

Intuitively, then, the higher the voltage (pressure), the higher the
current (flow rate).   Increase the resistance (partially close a valve or
use a narrower pipe) and for a fixed voltage (constant pressure), the
current (flow rate) will decrease.

With electricity, this relationship is what is known as linear: double the
voltage and all other factors remaining unchanged, the current will double
as well.  Increase it by a factor of 3 and the current will triple.  Halve
the resistance and for a constant voltage source, the current will double.
(For you who are hydraulic engineers, this is not quite true with plumbing
as turbulent flow sets in, but this is just an analogy, so bear with me.)

Note: for the following 4 items whether the source is Direct Current (DC)
such as a battery or Alternating Current (AC) from a wall outlet does not
matter.  The differences between DC and AC will be explained later.

The simplest electrical circuit will consist of several electrical
components in series - the current must flow through all of them to flow
through any of them.  Think of a string of Christmas lights - if one burns
out, they all go out because the electricity cannot pass through the broken
filament in the burned out bulb.

Note the term 'circuit'.  A circuit is a complete loop.  In order for
electricity to flow, a complete circuit is needed.

                          Switch (3)
               _____________/ ______________
              |                             |
              | (1)                         | (4)
      +-------+--------+                +---+----+
      |  Power Source  |                |  Load  |
      +-------+--------+                +---+----+
              |            Wiring (2)       |
1. Power source - a battery, generator, or wall outlet.  The hydraulic
   equivalent is a pump or dam (which is like a storage battery).  The
   water supply pipe in the street is actually only 'wiring' (analogous
   to the electric company's distribution system) from the water company's
   reservoir and pumps.

2. Conductors - the wiring.  Similar to pipes and aqueducts.  Electricity
   flows easily in good conductors like copper and aluminum.  These are like
   the insides of pipes.  To prevent electricity from escaping, an insulator
   like plastic or rubber is used to cover the wires.  Air is a pretty
   good insulator and is used with high power wiring such as the power
   company's high voltage lines but plastic and rubber are much more
   convenient as they allow wires to be bundled closely together.

3. Switch - turns current on or off.  These are similar to valves which
   do not have intermediate positions, just on and off.  A switch is not
   actually required in a basic circuit but will almost always be present.

4. Load - a light bulb, resistance heater, motor, solenoid, etc.  In
   true hydraulic systems such as used to control the flight surfaces of
   an aircraft, there are hydraulic motors and actuators, for example.

   With household water we usually don't think of the load.

Here are 3 of the simplest appliances:

* Flashlight: battery (1), case and wiring (2), switch (3), light bulb (4).

* Table lamp: wall outlet (1), line cord and internal wiring (2), power
  switch (3), light bulb (4).

* Electric fan, vacuum cleaner, garbage disposer: wall outlet (1), line
  cord and internal wiring (2), power switch (3), motor (4).

Now we can add some simple control devices:

5. Thermostat - a switch that is sensitive to temperature.  This is like an
   automatic water valve which shuts off if a set temperature is exceeded.
   Most thermostats are designed to open the circuit when a fixed or variable
   temperature is exceeded.  However, airconditioners, refrigerators, and
   freezers do the opposite - the thermostat switches on when the temperature
   goes too high.  Some are there only to protect against a failure elsewhere
   due to a bad part or improper use that would allow the temperature to
   go too high and start a fire.  Others are adjustable by the user and
   provide the ability to control the temperature of the appliance.

With the addition of a thermostat, many more appliances can be constructed
including (this is a small subset):

* Electric space heater (radiant), broiler, waffle iron: wall outlet (1),
  line cord and internal wiring (2), power switch (3) and/or thermostat (5),
  load (heavy duty heating element).

* Electric heater (convection), hair dryer: wall outlet (1), line cord
  and internal wiring (2), power switch (3) and/or thermostat (5), loads (4)
  (heating element and motor).

Electric heaters and cooking appliances usually have adjustable thermostats.

Hair dryers may simply have several settings which adjust heater power and
fan speed (we will get into how later).  The thermostat may be fixed and
to protect against excessive temperatures only.

That's it!  You now understand the basic operating principle of nearly all
small appliances.  Most are simply variations (though some may be quite
complex) on these basic themes.  Everything else is just details.

For example, a blender with 38 speeds just has a set of buttons (switches)
to select various combinations of motor windings and other parts to give
you complete control (as if you need 38 speeds!).  Toasters have a timer
or thermostat activate a solenoid (electromagnet) to pop your bread at
(hopefully) the right time.

5. Resistances - both unavoidable and functional.  Except for superconductors,
   all materials have resistance.  Metals like copper, aluminum, silver, and
   gold have low resistance - they are good conductors.  Many other metals
   like iron or steel are fair but not quite as good as these four.  One,
   NiChrome - an alloy of nickel and chromium - is used for heating elements
   because it does not deteriorate (oxidize) in air even at relatively high

   A significant amount of the power the electric company produces is lost
   to heating of the transmission lines due to resistance and heating.

   However, in an electric heater, this is put to good use.  In a flashlight
   or table lamp, the resistance inside the light bulb gets so hot that it
   provides a useful amount of light.

   A bad connection or overloaded extension cord, on the other hand, may
   become excessively hot and start a fire.

The following is more advanced - save for later if you like.

6. Capacitors - energy storage devices.  These are like water storage tanks
   (and similar is some ways to rechargeable batteries).

   Capacitors are not that common in small appliances but may be used with
   some types of motors and in RFI - Radio Frequency Interference - filters
   as capacitors can buffer - bypass - interference to ground.  The energy
   to power an electronic flash unit is stored in a capacitor, for example.
   Because they act like reservoirs - buffers - capacitors are found in the
   power supplies of most electronic equipment to smooth out the various
   DC voltages required for each device.

7. Inductors - their actual behavior is like the mass of water as it flows.
   Turn off a water faucet suddenly and you are likely to hear the pipes
   banging or vibrating.  This is due to the inertia of the water - it tends
   to want to keep moving.  Electricity doesn't have inertia but when wires
   are wound into tight coils, the magnetic field generated by electric
   current is concentrated and tends to result in a similar effect.  Current
   tends to want to continue to flow where inductance is present.

   The windings of motors and transformers have significant inductance but
   the use of additional inductance devices is rare in home appliances
   except for RFI - since inductance tends to prevent current from changing,
   it can also be used to prevent interference from getting in or out.

8. Controls - rheostats and potentiometers allow variable control of current
   or voltage.  A water faucet is like a variable resistor which can be
   varied from near 0 ohms (when on fully) to infinite ohms (when off).

  4.4) Ohm's Law

The relationships that govern the flow of current in basic circuits (without
capacitance or inductance - which is the case with many appliances) are
contained in a very simple set of equations known an Ohm's Law.

The simplest of these are:

                    V = I * R (1)
                    I = V / R (2) 
                    R = V / I (3)


     V is Voltage in Volts (or millivolts - mV or kilovolts - KV).
     I is current in amperes (A) or milliamps (mA) 
     R is resistance in Ohms (ohms), kilo-Ohms (K Ohms), or mega-Ohms (M Ohms).

Power in watts (W) is equal to voltage times current in a resistive circuit
(no capacitance or inductance).  Therefore, rearranging the equations above,
we also obtain:

                    P = V * I      (4)
                    P = V * V / R  (5)
                    P = I * I * R  (6)

For example:

* For a flashlight with a pair of Alkaline batteries (3 V) and a light bulb
  with a resistance of 10 ohms, we can use (2) to find that the current
  is I = (3 V) / (10 ohms) = .3 A.  The from (4) we find that the power
  is: P = (3 V * .3 A) = .9 W.

* For a blow-dryer rated at 1000 W, the current drawn from a 120 V line
  would be: I = P / V (by rearranging (4) = 1000 W / 120 V = 8.33 A.

As noted above:

* Increase voltage -> higher current.  (If the water company increases the
  pressure, your shower used more water in a given time.)

* Decrease resistance -> higher current.  (You have a new wider pipe installed
  between the street and your house.  Or, you open the shower valve wider.)

(Note that the common use of the term 'water pressure' is actually not
correct.  The most likely cause of what is normally described as low
water pressure is actually high resistance in the piping between your
residence and the street.  There is a pressure drop in this piping just
as there would be a voltage drop across a high value resistor.)

  4.5) DC and AC

While electricity can vary in any way imaginable, the most common forms
for providing power are direct current and alternating current:

A direct current source is at a constant voltage.  Displaying the voltage
versus time plot for such a source would show a flat line at a constant
level.  Some examples:

  * Alkaline AA battery - 1.5 V (when new).
  * Automotive battery - 12 V (fully charged).
  * Camcorder battery - 7.2 V (charged).
  * Discman AC adapter - 9 VDC (fully loaded).
  * Electric knife AC adapter - 3.6 VDC.

An Alternating Current (AC) source provides a voltage that is varying
periodically usually at 60 Hz (U.S.) or 50 Hz (many other countries).
Note that 1 Hz = 1 cycle per second.  Therefore, a 60 Hz AC voltage
goes through 60 complete cycles in each second.  For power, the shape
of the voltage is a sinusoid which is the smoothest way that anything
can vary periodically between two levels.

The nominal voltage from an AC outlet in the U.S. is around 115 VAC.  This
is the RMS (Root Mean Square) value, not the peak (0 to maximum).  In simple
terms, the RMS value of an AC voltage and the same value of a DC voltage
will result in identical heating (power) to a resistive load.  For example,
115 VAC RMS will result in the same heat output of a broiler as 115 VDC.

Direct current is used for many small motor driven appliances particularly
when battery power is an option since changing DC into AC requires some
additional circuitry.  All electronic equipment require various DC voltages
for their operation.  Even when plugged into an AC outlet, the first thing
that is done internally (or in the AC adapter in many cases) is to convert
the AC to various DC voltages.

The beauty of AC is that a very simple device - a transformer - can
convert one voltage into another.  This is essential to long distance
power distribution where a high voltage and low current is desirable to
minimize power loss (since it depends on the current).  You can see
transformers atop the power poles in your neighborhood reducing the
2,000 VAC or so from a local distribution transformer to your 115 VAC
(actually, 115-0-115 were the total will be used by large appliances like
electric ranges and clothes dryers).  That 2,000 VAC was stepped down
by a larger transformer from around 12,000 VAC provided by the local
substation.  This, in turn, was stepped down from the 230,000 VAC or
more used for long distance electricity transmission.  Some long distance
lines are over 1,000,000 volts (MV).

When converting between one voltage and another with a transformer, the
amount of current (amps) changes in the inverse ratio.  So, using 230 KV
for long distance power transmission results in far fewer heating losses
as the current flow is reduced by a factor of 2,000 over what it would
be if the voltage was only 115 V, for example.  Recall that power loss
from P=I*I*R is proportional to the square of the current and thus in
this example is reduced by a factor of 4,000,000!

Many small appliances include power transformers to reduce the 115 VAC
to various lower voltages used by motors or or electrical components.
Common AC adapters - often simply called transformers or wall warts -
include a small transformer as well.  Where their output is AC, this
is the only internal component other than a fuse or thermal fuse for
protection.  Where their output is DC, additional components convert
the low voltage AC from the transformer to DC and a capacitor smoothes
it out.

  4.6) Series and parallel circuits

Up until now, we have been dealing with the series circuit - all parts
are in a single line from power source, wiring, switches, load, and
anything else.  In a series circuit, the current must be the same
through all components.  The light bulb and switch in a flashlight
pass exactly the same value of amperes.  If there were two light bulbs
instead of one and they were connected in series - as in a Christmas
tree light set - then the current must be equal in all the bulbs but
the voltages across each one would be reduced.

The loads, say resistance heating elements, are now drawn with the
schematic symbol (as best as can be done using ASCII) for a resistor.

               _____________/ __________________
              |                 I -->           |
              |                        ^    ^   |
              |                        |    |   / R1
              |                        |   V1   \ Load 1
      +-------+--------+               |    |   /
      |  Power Source  |                    v__ |
      +-------+--------+              V(S)  ^   |
              |                             |   / R2
              |                        |   V2   \ Load 2
              |                        |    |   /
              |                        v    v   |

The total resistance, R(T), of the resistors in this series circuit is:

                    R(T) = R1 + R2                (7)

The voltage across each of the resistors would be given by:

                    V1 = V(S) * R1 / (R1 + R2)    (8)
                    V2 = V(S) * R2 / (R1 + R2)    (9)

The current is given by:

                    I = V(S)  / (R1 + R2)        (10)

However, another basic configuration, is also possible.  With a parallel
circuit, components are connected not one after the other but next to
one another as shown below:

               _____________/ ___________________________
              |                      I -->  |            |
              |                 ^           |            |
      +-------+--------+        |           / R1         / R2
      |  Power Source  |       V(S)         \ Load 1     \ Load 2
      +-------+--------+        |           /            /
              |                 v           |v I(1)      |v I(2)

Now, the voltages across each of the loads is necessarily equal but the
individual currents divide according to the relative resistances of each

The total resistance, R(T), of the parallel resistors in this circuit is:

                    R(T) = (R1 * R2) / (R1 + R2)  (11)

The currents through each of the loads would be given by:

                    I1 = V(S)/R1                  (12)
                    I2 = V(S)/R2                  (13)

The total current is given by:

                    I = I1 + I2                   (14)

Many variations on these basic arrangements are possible but nearly all can
be reduced systematically to a combination of series or parallel circuits.

Chapter 5) Appliance Troubleshooting

  5.1) SAFETY

Appliances run on either AC line power or batteries.  In the latter case,
there is little danger to you except possibly from burns due to short circuits
and heating effect or irritation from the caustic chemicals from old leaky

However, AC line power can be lethal.  Proper safety procedures must be
followed whenever working on live equipment (as well as devices which may
have high energy storage capacitors like TVs, monitors, and microwave
ovens).  AC line power due to its potentially very high current is actually
considerably more dangerous than the 30 KV found in a large screen
color TV!

These guidelines are to protect you from potentially deadly electrical shock
hazards as well as the equipment from accidental damage.

Note that the danger to you is not only in your body providing a conducting
path, particularly through your heart.  Any involuntary muscle contractions
caused by a shock, while perhaps harmless in themselves, may cause collateral
damage - there are many sharp edges inside this type of equipment as well as
other electrically live parts you may contact accidentally.

  5.2) Safety myths

For nearly all the appliances we will be covering, there is absolutely
no danger of electrical shock once the unit is unplugged from the wall
socket (not, however, just turned off, but unplugged).

You may have heard warnings about dangers from unplugged appliances.
Perhaps, these were passed down from your great great grandparents or
from local bar room conversation.

Except for devices with large high voltage capacitors connected to the
line or elsewhere, there is nothing inside an appliance to store a
painful or dangerous charge.  Even these situations are only present
in microwave ovens, fluorescent lamps and fixtures with electronic
ballasts, universal power packs for camcorders or portable computers,
or appliances with large motors.  Other than these, once an appliance
is unplugged all parts are safe to touch - electrically that is.  There
may still be elements or metal brackets that are burning hot as metal
will tend to retain heat for quite a while in appliances like toasters
or waffle irons.  Just give them time to cool.  There are often many
sharp edges on sheetmetal as well.  Take your time and look before you
leap or grab anything.

Go to [Next] segment

Go to [Table 'O Contents]

Written by Samuel M. Goldwasser. | [mailto]. The most recent version is available on the WWW server http://www.repairfaq.org/ [Copyright] [Disclaimer]