hi I'm Gwendolyn with iFixit and this is
basic skills where I show you the tips
and techniques of the skills involved
with repair today we're looking at how
to use a multimeter every fixer should
know their way around a multimeter which
has a million uses for testing
electronic components and circuits today
we're going over three of the most basic
functions for a multimeter testing
continuity voltage and resistance let's
start with testing continuity a
continuity test tells us whether two
things are electrically connected if
something is continuous an electrical
current can flow freely from one end to
the other if there's no continuity it
means there's a break somewhere in the
circuit this could indicate anything
from a blown fuse or bad solder joint to
a damaged cable to perform a continuity
test start by plugging in your probes
the black probe goes into the negative
terminal labeled comm or common and the
red probe goes into the volts ohms
milliamps terminal and make sure your
dial is set to the continuity mode that
is usually indicated by the icon that
looks like a sound wave if your screen
is like mine there will be a one on the
left of the display the multimeter test
continuity by sending a little current
through one probe and checking whether
the other probe receives it you can test
this out by touching the probes together
we get a beep and a reading the
connected probes make a complete circuit
the screen should display a value of
zero or near zero and the multimeter
will beep if this happens great you've
got continuity if you're not getting a
beep and the display remains at one or
changes to O L there's an open loop no
continuity we can see with this broken
cable that there's no reading for
continuity but maybe we can save the
rest of the cable so we're going to test
the wires before the break we get a beep
and a reading of near zero perfect you
can also use your multimeter to test DC
voltage it's hard to guess how much
juice is left in your battery so use
your multimeter to test voltage before
you throw them out
start with your probes plugged in
Blackley to come and read leads to the
port marked with the symbols for volts
ohms and mil amps now switch your
multimeter on and set the dial to the DC
voltage mode indicated by the V with a
straight line if you have a multimeter
with auto-ranging that's fantastic if
not you need to set the correct range
for the voltage you expect to measure if
you're not sure what the setting should
be just start with the highest and
adjust downward to get a more accurate
reading if you go too low your
multimeter will read one or oh L for
overload which just means the voltage is
out of range also be sure not to have
your meter set to amp your mode while
measuring voltage this can easily cause
your meter to blow a fuse on to the test
itself I found this 9-volt battery in a
drawer and I have no idea if it's good
or not to test this battery the red
probe goes on the positive terminal and
the black probe goes on the negative if
you're getting a negative reading that
just means that the leads are backwards
this is a brand new 9-volt battery so
I'm getting a reading just above 9 volts
our last suggestion is to use your
multimeter to test resistance for all
you hobbyist out there this one's for
you often times it's hard to remember
the color coding on resistors but your
multimeter can help with that resistance
is measured in ohms and indicated on
your multimeter by this symbol as with
our other test the black probe is
plugged into the comm port and the red
lead into ohms and this time we'll turn
our dial to the resistance mode just
like with voltage you need to set the
range to test resistance if you don't
have an auto range machine now place the
probes on the circuit you're testing if
the multimeter reads close to zero the
range is set too high for a good
measurement turn the dial to a lower
setting it doesn't matter which probes
go where resistance is non-directional
now you have the basic skills for using
your multimeter have fun stepping up
your repair game and let me know how it
goes you can find me on Twitter at
Gwendolyn Gaye and follow I fix it at
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