Good video, however should have clarified that it's AC voltage you are measuring from the wall to the AC/DC power adapter brick, then DC voltage from the AC/DC power adapter brick to the connector that plugs into the back of your laptop. Set your multimeter accordingly.
Important - When using a multi-meter to check voltage across the adapter, be sure to understand that the "brick" actually functions as a transformer. In other words, it converts AC power from the wall receptacle to DC power because the laptop battery is actually a DC battery. When checking voltage in the end of cord between the wall receptacle and where it connects to the "brick", be sure to set your multi-meter to ACV (AC Volts). 600V in UK and 200V in the U.S. If this checks out ok, you will need to reconfigure the multi-meter to check output voltage at the pin connector which is the connector (usually colored) that plugs directly to the laptop. When checking output voltage from the transformer or "brick" be sure to change the setting on the multi-meter to DCV or DC Volts....20V specifically for most meters. After changing the multi-meter to DCV, Insert one prong/lead from the multi-meter into the pin connector and touch the other prong/lead to the outside of the pin connector as demonstrated in the video. For diagnostics just remember: AC Power before the "brick" / DC power after the "brick".
What is the brick is just passing the AC without converting? Can this happen? If so then, using DC on multimeter to check the voltage on the plug end would break multimeter?
Dear Britec09 I thank you for your help, as I am just really getting into computer repair. I am an old electronics tech. A comment as a viewer. When setting up a multimeter it would help if you would also point out that you are turning it to AC volts or DC volts and explain when you should do each. Also when you have negative and positive volts you should not move the black lead just go to the negative post and your meter will show it as a negative volt. Thanks again for your help.
This is such a clear explanation. You got a gift! I want to mention my brother advised me to pay attention to the little linier diagram that has a + on one end a dot in the middle with a C over it and a minus - sign on the other end. Especially when attempting to replace the adapter with something you might have lying around.
Worthwhile noting that the multimeter has two voltage settings like the one in the video, you need to use the wave icon for AC (mains) and the line with dashed line underneath for DC (after the brick). Be careful checking mains and make sure you don't accidentally touch the prongs or touch them to each other!
Thank you for nice answer, just trying to help make everyones experience as good as I received from your video. Keep up the good work. You are doing a great service sharing with the rest of us "flawed humanbeings". Thanks again.
Thanks for the clear information and demonstration. I'm sure that it will come is use for those wary of using a multimeter with things connected to a live ac socket. I'd love to see a video showing how you can measure the power being used by a laptop/NUC during varying loads of usage to illustrate that despite an ac adapter having a certain rated usage, that this is the maximum and will not be the actual usage all of the time. Useful for those wanting to be as energy conscious as possible when choosing their devices.
Nice tutorial brian. Ive found the output cable often breaks close to the plug or powersupply end, plug end is easy to replace but the psu i end up carefully cutting round the lid seam with a hobby tool and mini grinding disk to gain access. And after the cable is done then using epoxy resin to seal it back up. Yes i am a tight sod :-)
Nice Video, be careful when testing mains with multimeters, make sure it's set for AC Volts and NEVER Amps. Also watch your fingers with those probes when they are measuring mains!
Good video, wish you could have shown how to test the amps. If the voltage reads fine but the amps are lower than the stated amount, the adapter could still fail to power the device.
You probably have the settings on the multimeter wrong when testing the volts. When you're testing the AC voltage you want to have it set on a v with a small ~ over it. When testing the DC voltage, it should be a v with two lines over it. One solid and the other dotted.
Please warn the users to be extremely careful while checking AC supply, a shock from an inadvertent touch at 240 volts can range from traumatizing to fatal. Sometimes the end connector is damaged and has exposed wires and bending by touching directly can lead to shock.
Hi Brian, it's a very helpful video, but do you think that it's wise to suggest people measure the 240v directly from the mains.. If set the multimeter up wrong or cross the probes, it could be toaster in the bath time.. thanks for the video though..
nice video :). Question: If there were something wrong with the power brick & it happened to be outputting more than 20v & you tested it with the multimeter set to 20v (like in the video), could you potential destroy the multimeter ?
Thanks. Very informative. How about if there is no pin inside the end connector/ barrel? ie it is just a barrel. Would just inserting the red probe inside it work?
Does it matter what leads you plug into the multi metre I see they have 3 holes to plug in and some of these metres show the red in the top hole and the black in the bottom with the middle hole free, they are the same metre like yours, M-380B but use different combinations with where the leads are plugged in. Does it matter?
yeah, don't get fake chargers. They won't work for long, if at all. Seen it so many times. With a laptop, fake charger will often not charge the battery.
Very clear for an electric dummy. That's me. My grandson bought a model tank in Singapore last week and the first time he tried to charge it here in Thailand, he couldn't. Can't take it back to the shop obviously so took it to and electrical repairer. The original charger is input 220v output 9.6 V 250ma. The shopsold us an adjustable charger which goes from 1.5v to 12v and 500ma max. The electrician told us to set the charger to 12volts? By your video this is suicide. It charged once and OK. now it doesn't. Any comments please. The new charger is crap and the adjuster buttons have fallen out already.
+ron martin Mhg In Thailand they use very cheap materials and this sounds like a defect cord inside the charger. Don't use it and contact a repairer. These problems are common from Thailand electric toys.
The power in a power supply refers to what important feature . . .? Do you know, Britec09. No, not Voltage. Voltage is actually a reference. Come on . . . think.
Great video! I learned a lot from u. Thank u very much! I see u just touch the pin while u are measuring. How come u don't get electrocuted? At minute 5:22 in video. If u touch the pins...or it looks like u are touching it but in fact u are not?!
The volts from the wall is fine, but when I test the plug after the brick, it gives a voltage reading that jumps all over the place, from 18v to 40v and in between. My adapter is rated for 18.5v. Also it won't charge my laptop anymore and forced a shutdown which prompted me testing it.
lol I'm guessing you have an auto-ranging multimeter. I'm guessing as it jumps all over the place from 18v to 40v that somewhere on the displays it reads mV (as in millivolts). So, you are really not jumping around between 18v to 40v but rather 18mV to 40mV, which means your brick has gone bad!
Hi, maybe you can help me with this question. I have a several ac adapters from several different devices I've had in the past and also from things I've got recently. I have tested them with two different multi-meters and some of them read out differently than what is posted on the box that plugs into the wall outlet. The device voltage that they are powering is supposed to be whats indicated on the ac adapter box and the devices function normally. Is it possible that the multi meters aren't reading the voltage correctly? The multi meters read the same voltage. Example: ac adapter box says 14v output both multi meters read 21v. I was building a circuit on a breadboard and was using the voltage that the multi meter read to figure out my resister values, the circuit seemed to function as if the voltage on the ac adapter box was correct. Does that make sense?
Hello, I have a Dell Laptop charger, where exactly is the +ve pin located? I've put the +ve probe on the center pin inside the jack and the -ve probe on the outer part of the jack, i'm getting no reading on the multimeter. when i place the +ve on the inside part on the jack, not the center pin I am getting a reading. please help.
I tried my router adapter,that is a WAG200g with a 12V-1A adapter,and got a reading of "1" in the scale of 20 V DC.Then upped the scale to 200 and it showed me 207-210.But 207 what?!?I did a second reading in another adapter of the same output and got about the same results and always 1 in the 20 volts scale.I watched the whole video and followed your instructions to the letter,what the hell am I doing wrong?In fact I know the adapters are ok,I did it just to learn the multimeter. Any thoughts?
When check the DC Voltage in Adapter it is showing DC voltage below -14.. So does that mean my adapter is not working as the laptop is not getting charged the output given in adapter is -19.5 DC Voltage.....Please help.....(Thank u for the video too)Very informative.. :)
Good video, however should have clarified that it's AC voltage you are measuring from the wall to the AC/DC power adapter brick, then DC voltage from the AC/DC power adapter brick to the connector that plugs into the back of your laptop. Set your multimeter accordingly.
Important - When using a multi-meter to check voltage across the adapter, be sure to understand that the "brick" actually functions as a transformer. In other words, it converts AC power from the wall receptacle to DC power because the laptop battery is actually a DC battery.
When checking voltage in the end of cord between the wall receptacle and where it connects to the "brick", be sure to set your multi-meter to ACV (AC Volts). 600V in UK and 200V in the U.S.
If this checks out ok, you will need to reconfigure the multi-meter to check output voltage at the pin connector which is the connector (usually colored) that plugs directly to the laptop. When checking output voltage from the transformer or "brick" be sure to change the setting on the multi-meter to DCV or DC Volts....20V specifically for most meters. After changing the multi-meter to DCV, Insert one prong/lead from the multi-meter into the pin connector and touch the other prong/lead to the outside of the pin connector as demonstrated in the video.
For diagnostics just remember: AC Power before the "brick" / DC power after the "brick".
What is the brick is just passing the AC without converting? Can this happen? If so then, using DC on multimeter to check the voltage on the plug end would break multimeter?
That's for the tips and advise Patrick, there is always something I miss.
Dear Britec09
I thank you for your help, as I am just really getting into computer repair. I am an old electronics tech. A comment as a viewer. When setting up a multimeter it would help if you would also point out that you are turning it to AC volts or DC volts and explain when you should do each. Also when you have negative and positive volts you should not move the black lead just go to the negative post and your meter will show it as a negative volt. Thanks again for your help.
This is such a clear explanation. You got a gift! I want to mention my brother advised me to pay attention to the little linier diagram that has a + on one end a dot in the middle with a C over it and a minus - sign on the other end. Especially when attempting to replace the adapter with something you might have lying around.
Thanks for this video from Texas. Found out that my charger is bad and I didn't have to buy a new laptop. Cheers!
Worthwhile noting that the multimeter has two voltage settings like the one in the video, you need to use the wave icon for AC (mains) and the line with dashed line underneath for DC (after the brick). Be careful checking mains and make sure you don't accidentally touch the prongs or touch them to each other!
Thank you for nice answer, just trying to help make everyones experience as good as I received from your video. Keep up the good work. You are doing a great service sharing with the rest of us "flawed humanbeings". Thanks again.
Thanks for the clear information and demonstration.
I'm sure that it will come is use for those wary of using a multimeter with things connected to a live ac socket.
I'd love to see a video showing how you can measure the power being used by a laptop/NUC during varying loads of usage to illustrate that despite an ac adapter having a certain rated usage, that this is the maximum and will not be the actual usage all of the time.
Useful for those wanting to be as energy conscious as possible when choosing their devices.
Blessings brother, the paper clip was exactly what I needed to test the DC on my charger!
Your welcome, glad it helped you solve your issue.
Nice tutorial brian.
Ive found the output cable often breaks close to the plug or powersupply end, plug end is easy to replace but the psu i end up carefully cutting round the lid seam with a hobby tool and mini grinding disk to gain access.
And after the cable is done then using epoxy resin to seal it back up.
Yes i am a tight sod :-)
@Britec09 el-cheapo is fine for normal computer tech work like that!
Thank you thank you thank you for making this video - now all I have to do is obtain a multimeter to test whether the problem lies in the adapter...
Nice Video, be careful when testing mains with multimeters, make sure it's set for AC Volts and NEVER Amps. Also watch your fingers with those probes when they are measuring mains!
@jmitservices Yeah that's a El Cheapo Multimeter, I have a fluke model which is real good.
Thanks for making and sharing this video! You saved me from having to buy a new adapter.
Good video - clear, concise yet comprehensive.
As always a clear, lucid and informative video. Thx Brian.
spot on advice. Helped more than you know!
Cheers.
Thanks, glad you liked it.
Good video, wish you could have shown how to test the amps. If the voltage reads fine but the amps are lower than the stated amount, the adapter could still fail to power the device.
You probably have the settings on the multimeter wrong when testing the volts. When you're testing the AC voltage you want to have it set on a v with a small ~ over it. When testing the DC voltage, it should be a v with two lines over it. One solid and the other dotted.
Great video.The right badly needed information.Thanks a mill!!
Shocking video Brian shocking :) Very good video mate! Could you show a video about how to test for amps? Thanks.
very clear and concise video Brian !!!. good job
Nice Video Brian.. Keep them coming....
Please warn the users to be extremely careful while checking AC supply, a shock from an inadvertent touch at 240 volts can range from traumatizing to fatal. Sometimes the end connector is damaged and has exposed wires and bending by touching directly can lead to shock.
Good video - clear, concise and comprehensive.
Excellent and informative video. Answered all my questions. Many thanks.
Nice video Brian. Did you use the C920? Looks very good..
Thanks for the strategies you have discussed here.
Hi Brian, it's a very helpful video, but do you think that it's wise to suggest people measure the 240v directly from the mains.. If set the multimeter up wrong or cross the probes, it could be toaster in the bath time.. thanks for the video though..
@mitchman5155 yeah it was the c920
nice video :).
Question: If there were something wrong with the power brick & it happened to be outputting more than 20v & you tested it with the multimeter set to 20v (like in the video), could you potential destroy the multimeter ?
This removes the guesswork. Thank you!
Thanks mate, this saved me some money, much appreciated.
Thanks. Very informative. How about if there is no pin inside the end connector/ barrel? ie it is just a barrel. Would just inserting the red probe inside it work?
thanks! it was useful to test my faulty laptop charger!
Thank you! Very clear and concise. Helped me out tons. Cheers!
Thanks Rob, but i am just a common guy with a london accent
Your welcome.
YOU GOT A NEW CAMERA!!!!!!!!!!!!!!!!!!!
Cheers mate.
Does it matter what leads you plug into the multi metre I see they have 3 holes to plug in and some of these metres show the red in the top hole and the black in the bottom with the middle hole free, they are the same metre like yours, M-380B but use different combinations with where the leads are plugged in. Does it matter?
Thank you for explaining properly and for Americans
Very helpful for this newbee - much thanks
Thank you for the clear explanation. Very good.
Thank you! This was just what I needed to get me started. I was able to diagnose the issue and fix it. Can I call myself an electrician now? :)
Awesome video. Just the answers I needed.
Good video! A good multimeter is a must have!!
Similar question. If the charger wasn't working then the charge would be 0 volts?? I'm getting that on my charger.
Hey Brian very informative video thanks very much!
I Also enjoyed listening to you on podnutz :)
thank you so much for your explanation! it was very informative and clear.
yeah, don't get fake chargers. They won't work for long, if at all. Seen it so many times. With a laptop, fake charger will often not charge the battery.
Very clear for an electric dummy. That's me.
My grandson bought a model tank in Singapore last week and the first time he tried to charge it here in Thailand, he couldn't. Can't take it back to the shop obviously so took it to and electrical repairer. The original charger is input 220v output 9.6 V 250ma. The shopsold us an adjustable charger which goes from 1.5v to 12v and 500ma max. The electrician told us to set the charger to 12volts? By your video this is suicide. It charged once and OK. now it doesn't. Any comments please. The new charger is crap and the adjuster buttons have fallen out already.
+ron martin Mhg In Thailand they use very cheap materials and this sounds like a defect cord inside the charger. Don't use it and contact a repairer. These problems are common from Thailand electric toys.
Dankje deze video heeft mijn vragen beantwoordt.
240V standard, the absolute madmen
Excellent! Thank you! This helped me a lot. Cheers!
This was so useful. Thanks a bunch!
Excellent video, thank you!
Hi, this video was very helpful, thank you very much and keep up with the good work. cheers
The power in a power supply refers to what important feature . . .?
Do you know, Britec09.
No, not Voltage. Voltage is actually a reference. Come on . . . think.
same here, was waiting for him to test the current
brilliant tutorial, thanks, nice and clear...
99% of laptop cords are clover style -not the 2 pin like you are showing us.
you explained so well.. thanks
Great video! I learned a lot from u. Thank u very much! I see u just touch the pin while u are measuring. How come u don't get electrocuted? At minute 5:22 in video. If u touch the pins...or it looks like u are touching it but in fact u are not?!
Mr Mo that voltage is low enough that you don't even feel that. Current flows always on the less resistant part. In that case, the cable.
touch to each other while either one is touching the mains I meant
Thank you! and also thanks
for commenting for United States differences
Thanks for the lesson!!
great video
Well tilly you should not be attempting this type of job if your not a tech.
@smallpebble7 Thanks mate
very good explanation!... thank you.
The volts from the wall is fine, but when I test the plug after the brick, it gives a voltage reading that jumps all over the place, from 18v to 40v and in between. My adapter is rated for 18.5v. Also it won't charge my laptop anymore and forced a shutdown which prompted me testing it.
lol I'm guessing you have an auto-ranging multimeter. I'm guessing as it jumps all over the place from 18v to 40v that somewhere on the displays it reads mV (as in millivolts). So, you are really not jumping around between 18v to 40v but rather 18mV to 40mV, which means your brick has gone bad!
Thanks for your help!
thanks, it was very useful and solving problem
Can you make a video on how to test Apple macbook charger
Thanks very much. This helped a great deal.
Nice and clear. Thanks!
can 1V make difference ? 18.5 vs 19.5 ?
Thanks man!
Hi, maybe you can help me with this question. I have a several ac adapters from several different devices I've had in the past and also from things I've got recently. I have tested them with two different multi-meters and some of them read out differently than what is posted on the box that plugs into the wall outlet. The device voltage that they are powering is supposed to be whats indicated on the ac adapter box and the devices function normally. Is it possible that the multi meters aren't reading the voltage correctly? The multi meters read the same voltage. Example: ac adapter box says 14v output both multi meters read 21v. I was building a circuit on a breadboard and was using the voltage that the multi meter read to figure out my resister values, the circuit seemed to function as if the voltage on the ac adapter box was correct. Does that make sense?
Super video: you explain it so clearly, even for Muppets such as myself. Thank you.
Huge help, appreciate the detail and clear instructions. So easy even an American can do it ;)
This guys voice is awesome
Hello, I have a Dell Laptop charger, where exactly is the +ve pin located? I've put the +ve probe on the center pin inside the jack and the -ve probe on the outer part of the jack, i'm getting no reading on the multimeter. when i place the +ve on the inside part on the jack, not the center pin I am getting a reading. please help.
great work!
what about if the adapter has 3 holes instead of 2 [3-probe]? Is the upper one hole for earth?
I tried my router adapter,that is a WAG200g with a 12V-1A adapter,and got a reading of "1" in the scale of 20 V DC.Then upped the scale to 200 and it showed me 207-210.But 207 what?!?I did a second reading in another adapter of the same output and got about the same results and always 1 in the 20 volts scale.I watched the whole video and followed your instructions to the letter,what the hell am I doing wrong?In fact I know the adapters are ok,I did it just to learn the multimeter.
Any thoughts?
What about the power adapters that need load to output proper voltage?
The image is giving me a 403 error, mate.
My battery output is 19v but my reading is giving me 21v, and my laptop is burn on the connetor side, would that be the reason?
Thanks alot that video was very helpfull!
hi did you turn it on at the wall before you tested the power cable
How to confirm the power of the "clone" adapter? I mean how to check the current (the video explain how to measure voltage)?
My acumulator has voltaje reading unpluged :)
Very good!
Very good, thanks.
When check the DC Voltage in Adapter it is showing DC voltage below -14..
So does that mean my adapter is not working as the laptop is not getting charged the output given in adapter is -19.5 DC Voltage.....Please help.....(Thank u for the video too)Very informative.. :)