TECH: Why is it best to remove a fuse to test it?
spike
OK but all the rest of the pf solenoids were not working. I had
'buzzed' the under playfield fuse with my meter - touching both the
fuse holder at both sides and the metal caps of the fuse and it
bleeped. To me, that meant the fuse was not blown.
To cut a long story short, I came back to this fuse after testing and
swapping other stuff and having seen a post from Lloyd recommending to
remove the fuse for testing with meter set to ohms. Bizarrely and for
me, fortunately it failed the test ad after replacing with a new fuse,
all is well.
So why do fuses have to be removed to check?
Spike
johninc
bcfc-e52...@o11g2000yql.googlegroups.com:
> So why do fuses have to be removed to check?
> Spike
>
Because something in the circuit is giving you a false reading.
--
inc
Lloyd Olson
Not everything checks right, in circuit. When I pull one I can see if the
holder is gripping them tight. In my hand I can check that the metal ends
aren't loose. With a meter I can see if it's good or bad. And rare, but I
have had some, usually the small T fuses, that are partially blown and
actually are drawing ohms, thus current goes through but not enough to do
it's job.
Some people don't pull them, I like to. When I fix something I like to keep
moving forward, not get stuck going back and forth. LTG :)
"spike" <spikepho...@gmail.com> wrote in message
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cody chunn
that sometimes you can read all the way around the circuit instead of
through the fuse.
Alternately, set your meter to volts and test the voltage on each side of
the fuse with the machine on.
However, IMO it's best to pull the fuse because the removal and
reinstallation tests the integrity of the fuse and clips.
--
-cody
--CARGPB4
"spike" <spikepho...@gmail.com> wrote in message
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m6onz5a
I was thinking putting the meter on the fuse while it's still
connected is completing the circuit. You don't have to remove the
whole fuse just one side to test it. I made a J-Hook and get under one
side and just pull one side off and check it with a meter.
Woz
The continuity check on most meters will beep when the resistance
measured is below a certain value (say 40 ohms). If you remove the
fuse and measure the resistance back into the circuit (across the fuse
terminals with the power switched OFF!) it will more than likely be
<40 ohms and the meter will beep. As suggested, the best way to test
is to lift one side of the fuse and measure the resistance of the
fuse.
Woz
spike Nottingham, England
Spike
Nottingham, England
RonK...@aol.com
There are pros and cons to removing fuses for checking.
Pros:
1. Get a definate good or bad with an ohmmeter 99.9% of the time
2. Bad fuse clips will show up
Cons:
1. Fuse integrity is compromised every time it is fooled with. Just
like removing a light bulb from a socket, it's more likely to fail
soon after fooling with it needlessly.
2. Guys that can't hold small objects may drop the fuse and damage or
lose it.
3. Very possible to damage a perfectly good fuse clip and each removal/
reinstall puts strain on the clips.
4. Possible to get a nice electric shock. Probably not on pinball
machines, but in TVs and such, many times up to 200vdc can be stored
even after the unit is unplugged on fuses. Touch that fuse with your
hand and whip it out of there real fast.
5. Huge waste of time, when volts check will reveal a bad fuse in
about 1 second test.
So you can see the cons outweigh the pros at least 2 to 1.
cody chunn
full potential voltage but can fail to pass enough current. Better to pop it
out and verify the clips are ok and not tarnished or rusted inside where you
can't see with the fuse installed.
--
-cody
--CARGPB4
<RonK...@aol.com> wrote in message
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