Test Laptop AC Power Adapter with Multimeter by Britec

# How to Test an AC Power Adapter for a Laptop: A Step-by-Step Guide

## Introduction

If you're experiencing issues with your laptop's power adapter—such as no power delivery or failure to boot up—the first thing you should do is test it. The best way to determine if the adapter is faulty is by swapping it with a known good one. However, if you don't have a spare, this guide will show you how to use a cheap multimeter (available for around £6 from Maplin) to perform a quick and effective test.

## Understanding the Components of an AC Power Adapter

The power adapter you're testing has several key components:

1. **Wall Plug**: This is where the adapter connects to the mains power supply. In the UK, it receives 240 volts, while in the US, it’s 110 volts.

2. **Power Brick**: This device steps down the voltage from the wall plug (e.g., 240V in the UK) to a lower voltage required by your laptop (e.g., 19.5V).

3. **Connector Cable**: The cable connects the power brick to your laptop, delivering the regulated power supply.

The adapter works by converting high-voltage AC power from the wall into a safe, low-voltage DC power that your laptop can use. Testing each component ensures that the issue isn't with any specific part of the adapter.

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## Testing the Wall Plug Connector

Before testing the rest of the adapter, it’s essential to check the connection at the wall plug. This is often where issues occur due to bending or pulling the plug over time, which can cause internal breaks.

1. **Plug in the Adapter**: Insert the wall plug into a mains socket and ensure it’s securely connected.

2. **Use the Multimeter**: Set your multimeter to the 600V range (since 200V is insufficient for UK voltage).

3. **Test the Plug**: Touch the multimeter’s probes to the live and neutral pins of the wall plug. If you see a reading close to 240V (e.g., 246V), the wall plug is functioning correctly.

To check for breaks in the connection, gently move the plug around while monitoring the multimeter reading. If the reading fluctuates or drops, it indicates a potential break in the wiring, and you’ll need to replace this part instead of the entire adapter.

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## Inspecting and Testing the Power Brick

The power brick is responsible for converting the high voltage from the wall plug into the lower voltage needed by your laptop (e.g., 19.5V).

1. **Visual Inspection**: Look for any visible damage or burn marks on the power brick. These are clear signs of failure.

2. **Testing the Pins**: Use the multimeter to test the pins on the power brick’s output side.

- Set your multimeter to the 20V range (since testing at 200V would risk damaging the device or giving inaccurate readings).

- Touch the red probe to the center pin (positive) and the black probe to the outer pin (negative). You should see a reading close to 19.5V.

If you’re unable to access the pins due to their small size, use a paperclip to gently insert into the connector and repeat the test. This method ensures accurate readings without damaging the adapter further.

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## Replacing or Repairing the Adapter

If your tests reveal that the power brick is faulty, consider whether it’s worth replacing versus purchasing a new adapter. Many adapters are expensive, but you can find cloned versions or alternative power supplies as long as they match the voltage and amperage requirements of your laptop.

- **Voltage vs. Amps**: Always prioritize using the correct voltage for your laptop. While amps can vary slightly (e.g., 8.2A is acceptable if it’s paired with the right voltage), never exceed the recommended voltage rating.

- **Replacement Options**: If replacing the end connector or a specific part isn’t cost-effective, consider purchasing an entirely new adapter. Ensure it has the correct model number and connector type for your laptop (e.g., VGP AC19V15).

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## Conclusion

Testing an AC power adapter for a laptop is a straightforward process that can save you from unnecessary expenses by identifying specific faults within the adapter’s components. By using a multimeter to test each part—starting from the wall plug, through the power brick, and finally the connector cable—you can determine whether the issue lies with one component or the entire adapter.

If you enjoyed this guide, don’t forget to subscribe for more videos on troubleshooting and repair! You can also follow me on [Facebook](insert link) and [Twitter](insert link) to stay updated on new content. Thanks for watching, and I’ll see you in the next video!

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*End of Article*

"WEBVTTKind: captionsLanguage: enwhat you guys got another video here for you this one's on how to test an AC power adapter for a laptop now you may be having issues with your power adapter uh maybe not be getting no power to the actual laptop maybe not booting up and this is the first thing that you need to test okay now if you don't have a spare power adapter so cuz that's the best way to do it is swap it out with a known good one and actually test it that way but if you haven't got one then I'm going to show you how to do it with a cheap multi meter reader that you can actually get for about6 from maplin and do a quick test with this okay so let's uh go about have a look at the connectors for the actual power adapter now this is the actual part that comes from the wall so we got the the part that goes in the wall 240 volts in the UK and it will come out of this end which is 240 volts in the states it will be 110 uh so from here in the UK 240 volts will then go into the power brick and once it goes into here this little device here will step it down to 19 in this case 19.5 volts so let me have a show you here you'll see that 19.5 volts and that will get step down to that and then it will go into this cable connector which goes into the laptop okay okay and that's how it works so what we're going to do is test all these connectors to make sure we're getting the right sort of power all the way through if we haven't got one to test to okay so this is the part we're going to test and another thing to remember is you see these bend a lot of people bend and pull these about over the course of time they get pulled in the wall and this sometimes breaks so I've seen people testing these and they uh don't get no power or they do get power and this is a good way to do you test it up and then you move it about a little bit just to see if it fluctuates and if it does then you know there's a problem with the actual disconnector and you can always replace this part and this means this part is good so you don't have to buy a whole new piece so just bear that in mind okay so let's plug this in and see how we test it okay so we got that plugged in now and uh these are the connectors we're going to do be using these prongs on the multimeter now this is the positive the Red's the positive and this is the negative so it doesn't really matter which way you do this either way the red can go into either one of these okay it doesn't really matter what is important is this part which is how we're going to set it up so we need to make sure that we got this on the right one now if you look here I'll try and get this focused in you see 200 and 600 now if you're in the States 200's going to be ample in the UK okay we need 600 cuz 200 is not going to cut the mustard so what we need to do there is just put that onto 600 going to get our connector here and we're just going to stick the red prong in and then the black one and you should see a reading there so we're getting 200 we're getting 246 so that's good so we know this is good now good thing to do here at this point is like I said is move this part about just to make sure that you're not getting a break in the connection there might be power there now but the last thing you want to think of in case you move this and then suddenly the connection drops and then all of a sudden you know that this part is then bad so then we can replace this so now we know this is good okay let's just reset this back to zero now what we're going to do now is uh test this part of the connector and this is the next part we're going to test and as you can see there should be a little tiny pin inside here don't know if you can see that there's a little tiny pin and that's the positive so we need to make sure that the red connector is going to get on into that little red into that little pin inside there so we need to plug this into our power brick to make sure we got power to itwi it's not going to work okay so we've got that power in there now we need to change our settings onside our multimeter here to 20 now because it's going to step down to 19 volts so set setting this at 200 would not be a good idea so we want to actually set that to 20 there that'll do okay so this is where we need to get our red prong now this is important you need to make sure that the red one is going on the central pin like so and this can be B pretty tricky on camera so I'm just going to try and do my best here so I'm going to try and hold on to this like so and that's in the center and then I just want to touch the black side onto there like so and that's how you want it and you can see in the background so the next thing you want to do is also make sure while you're getting that reading that you give that a little Bend to make sure that the brake is not inside here okay now also cuz then you can just replace the end connector okay you don't have to do the whole lot but sometimes it's just as cheap just to replace the whole lot so what happens if we can't get the pin inside here if the all is smaller now I've seen some of these connectors are very very small and you you can't get a probe in there inside these little connectors here well what you need to do is use a paperclip and you get a paper clip and you stick the paper clip inside there like so and then you do the same thing okay so the paper clip's inside and then you touch the red on the paperclip and the black on there and you'll get a reading okay it's as simple as that so now we know that the actual power adapter is fine so we need to have a look at the details here on the power brick now what happens if the power brick is failed and we need to replace it well that's also important cuz we need to make sure just turn that off need to make sure that we're getting the right information and as I said to you before if you look at this this will give you all the information that you need okay now if you look there this is the actual uh model number vgp ac1 9 v15 and also there's the actual plus and the minus it tells you the end the connector shows you the actual way to test it if you wanted to that's the plus and there's the minus and that's the end part on that connector there that I just showed you okay another bit of in important information let me try and get this uh focused in here you can see 19.5 volts now that is the voltage for this adapter if you start using voltage of more than that and then plugging that into a laptop you're going to fry the Bol or do damage to the laptop itself okay so you need to make sure that you stick to the voltage do not put More Voltage in okay that's an important part so if you're buying one of these adapters that have got uh different types of voltage you need to make sure you use the right voltage for that laptop the amps is there now the amps you can actually go up two or more so the same so if you bought one of these and it said 8.2 amps and it had 19.5 volts that will be fine okay what you mustn't do obviously is change the volts so the amps can go up but the voltage must stay the same now I've seen that people get that confused but that is exactly how to do it okay so basically what you do here is you can purchase one of these now obviously Sony are very pricey so what I would advise you to do is get yourself a cloned version of one of these a different type of version or patent part uh and buy one of these and uh you'll be pretty much good to go as long as it's got the right voltage and the amps it really sort of doesn't matter they don't they're very rarely going to go up too high but it might be a little bit of difference but the voltage is most important okay and I think that's probably about it for this video that's how you test an AC power adapter for a laptop and uh hope you enjoyed these videos my name is Brian from brch .co.uk if you enjoy these videos please remember guys hit that subscribe button and show your support also rate and favorite all my videos if you enjoy them and also if you haven't joined uh my Facebook page yet then uh like my Facebook page you can see that at the top of my banner on my channel and also follow me on Twitter if you like and uh and I'll be making more videos again in the future so thanks again guys for your support bye for nowwhat you guys got another video here for you this one's on how to test an AC power adapter for a laptop now you may be having issues with your power adapter uh maybe not be getting no power to the actual laptop maybe not booting up and this is the first thing that you need to test okay now if you don't have a spare power adapter so cuz that's the best way to do it is swap it out with a known good one and actually test it that way but if you haven't got one then I'm going to show you how to do it with a cheap multi meter reader that you can actually get for about6 from maplin and do a quick test with this okay so let's uh go about have a look at the connectors for the actual power adapter now this is the actual part that comes from the wall so we got the the part that goes in the wall 240 volts in the UK and it will come out of this end which is 240 volts in the states it will be 110 uh so from here in the UK 240 volts will then go into the power brick and once it goes into here this little device here will step it down to 19 in this case 19.5 volts so let me have a show you here you'll see that 19.5 volts and that will get step down to that and then it will go into this cable connector which goes into the laptop okay okay and that's how it works so what we're going to do is test all these connectors to make sure we're getting the right sort of power all the way through if we haven't got one to test to okay so this is the part we're going to test and another thing to remember is you see these bend a lot of people bend and pull these about over the course of time they get pulled in the wall and this sometimes breaks so I've seen people testing these and they uh don't get no power or they do get power and this is a good way to do you test it up and then you move it about a little bit just to see if it fluctuates and if it does then you know there's a problem with the actual disconnector and you can always replace this part and this means this part is good so you don't have to buy a whole new piece so just bear that in mind okay so let's plug this in and see how we test it okay so we got that plugged in now and uh these are the connectors we're going to do be using these prongs on the multimeter now this is the positive the Red's the positive and this is the negative so it doesn't really matter which way you do this either way the red can go into either one of these okay it doesn't really matter what is important is this part which is how we're going to set it up so we need to make sure that we got this on the right one now if you look here I'll try and get this focused in you see 200 and 600 now if you're in the States 200's going to be ample in the UK okay we need 600 cuz 200 is not going to cut the mustard so what we need to do there is just put that onto 600 going to get our connector here and we're just going to stick the red prong in and then the black one and you should see a reading there so we're getting 200 we're getting 246 so that's good so we know this is good now good thing to do here at this point is like I said is move this part about just to make sure that you're not getting a break in the connection there might be power there now but the last thing you want to think of in case you move this and then suddenly the connection drops and then all of a sudden you know that this part is then bad so then we can replace this so now we know this is good okay let's just reset this back to zero now what we're going to do now is uh test this part of the connector and this is the next part we're going to test and as you can see there should be a little tiny pin inside here don't know if you can see that there's a little tiny pin and that's the positive so we need to make sure that the red connector is going to get on into that little red into that little pin inside there so we need to plug this into our power brick to make sure we got power to itwi it's not going to work okay so we've got that power in there now we need to change our settings onside our multimeter here to 20 now because it's going to step down to 19 volts so set setting this at 200 would not be a good idea so we want to actually set that to 20 there that'll do okay so this is where we need to get our red prong now this is important you need to make sure that the red one is going on the central pin like so and this can be B pretty tricky on camera so I'm just going to try and do my best here so I'm going to try and hold on to this like so and that's in the center and then I just want to touch the black side onto there like so and that's how you want it and you can see in the background so the next thing you want to do is also make sure while you're getting that reading that you give that a little Bend to make sure that the brake is not inside here okay now also cuz then you can just replace the end connector okay you don't have to do the whole lot but sometimes it's just as cheap just to replace the whole lot so what happens if we can't get the pin inside here if the all is smaller now I've seen some of these connectors are very very small and you you can't get a probe in there inside these little connectors here well what you need to do is use a paperclip and you get a paper clip and you stick the paper clip inside there like so and then you do the same thing okay so the paper clip's inside and then you touch the red on the paperclip and the black on there and you'll get a reading okay it's as simple as that so now we know that the actual power adapter is fine so we need to have a look at the details here on the power brick now what happens if the power brick is failed and we need to replace it well that's also important cuz we need to make sure just turn that off need to make sure that we're getting the right information and as I said to you before if you look at this this will give you all the information that you need okay now if you look there this is the actual uh model number vgp ac1 9 v15 and also there's the actual plus and the minus it tells you the end the connector shows you the actual way to test it if you wanted to that's the plus and there's the minus and that's the end part on that connector there that I just showed you okay another bit of in important information let me try and get this uh focused in here you can see 19.5 volts now that is the voltage for this adapter if you start using voltage of more than that and then plugging that into a laptop you're going to fry the Bol or do damage to the laptop itself okay so you need to make sure that you stick to the voltage do not put More Voltage in okay that's an important part so if you're buying one of these adapters that have got uh different types of voltage you need to make sure you use the right voltage for that laptop the amps is there now the amps you can actually go up two or more so the same so if you bought one of these and it said 8.2 amps and it had 19.5 volts that will be fine okay what you mustn't do obviously is change the volts so the amps can go up but the voltage must stay the same now I've seen that people get that confused but that is exactly how to do it okay so basically what you do here is you can purchase one of these now obviously Sony are very pricey so what I would advise you to do is get yourself a cloned version of one of these a different type of version or patent part uh and buy one of these and uh you'll be pretty much good to go as long as it's got the right voltage and the amps it really sort of doesn't matter they don't they're very rarely going to go up too high but it might be a little bit of difference but the voltage is most important okay and I think that's probably about it for this video that's how you test an AC power adapter for a laptop and uh hope you enjoyed these videos my name is Brian from brch .co.uk if you enjoy these videos please remember guys hit that subscribe button and show your support also rate and favorite all my videos if you enjoy them and also if you haven't joined uh my Facebook page yet then uh like my Facebook page you can see that at the top of my banner on my channel and also follow me on Twitter if you like and uh and I'll be making more videos again in the future so thanks again guys for your support bye for now\n"