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Okay, let's look at a scenario where your LED is on and it stays on and it won't turn off
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What do you do? One scenario for this to be happening is that you have a short which is keeping the LED on and
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when you press the button nothing seems to happen. An example of this would be as this particular switch here, you can see
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see it has four pins. There's two on this side and two on the other side. And you can see here
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that I have this yellow jumper wire going to the left pin on this side. This is from the
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positive side of the power supply. And then you see that I've placed the resistor
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on this side of the push button switch which is on the right side or right terminal of the push button switch if I were to have placed the resistor where the terminal is now on the left terminal of the push button switch
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now in line with the yellow jumper wire from the positive supply
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Let me get my orange stick here. Now the power supply comes in through the switch and straight through to this resistor
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And let's say that my LED was shifted over in line. with this other side or the other leg of the resistor through the LED to ground Now if I press the button nothing happens
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The LED stays on. What's happening is for this particular kind of switch
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this switch has four leads, four legs, two on this side, and two on this side
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The current is coming from the, positive power supply through the yellow jumper wire through the switch and
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through the switch these two contacts in the switch on this side are connected with
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each other and it's going straight through the resistor and straight through
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the LED to ground so since the contacts with inside this switch are connected the
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current is allowed to go straight through the switch the resistor and the
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LED to ground even if I press the button like I said the LED still stays on So you need to make sure that you place in this case for this kind of switch place the resistor to where it on
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to where it's on this leg here of this switch. So our power, coming from our power supply, from the positive side
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through our yellow jumper wire here, to the switch. But at this point, there's no contact between this side
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and this side of the switch. They're separate. So in order for a connection to be made from this side to this side, you have to press the button
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As you can see here, the LED lights up