AC/DC Power adapter
AC/DC power adapter as known as power supply or power brick converts the high voltage AC power from a wall outlet into the low voltage DC power needed for your laptop.
The AC/DC adapter provides power for the laptop and charges the battery. It’s very important to use the right adapter for your laptop.
If you are looking for a new adapter, you should check the following:
1. Your new adapter must have exactly the same plug (adapter tip) as the original one.
2. Your new adapter must output exactly the same voltage as the original one.
3. Polarity on the new adapter’s plug must be the same as on the original one.
You can find the output voltage and amperage on the adapter’s label. As you see on the picture below, my adapter outputs 19V-3.42A.
When you buy a new adapter, you can follow this rule:
The output voltage must be the same, the amperage could be the same or higher than on the original power adapter.
For example, if my laptop requires 19v-3.42A adapter, I can safely use 19v-3.95A adapter.
HOW TO TEST OR REPAIR POWER ADAPTERS.
Most newer laptop power adapters are sealed and you cannot repair them. If the adapter is dead, you’ll have to buy a new one.
1. How can you tell if the AC adapter is dead? You can test it with a voltmeter. On the picture below I’m testing a 15V adapter and as you see the output is 15.45V. It’s pretty normal and there is nothing wrong if the output voltage is a little bit higher but if you are getting 0V, the adapter is definitely bad.
2. If you accidentally damaged the adapter plug, you can replace it with a new one. Just make sure the new plug has the same size as the old one. Cut off the old damaged plug and solder a new one. You can search for a new adapter plug (adapter tip) here.
Laptop parts | Repair Man | 
December 26, 2008 2:51 pm
171 Responses to “AC/DC Power adapter”
Pages: « 7 6 5 [4] 3 2 1 » Show All
Pages: « 7 6 5 [4] 3 2 1 » Show All
December 1st, 2010 at 12:24 pm
Ken,
Don’t do it. You can (and most likely will) damage the motherboard.
You’ll have to fund a new adapter with correct voltage.
December 1st, 2010 at 12:18 pm
Sony labtop adapter die. It output 19.5V draw 3.9 A total of 76W
Good toshiba labtop adapter. Output 15V 5A = 75W
Will it be OK to do following:
Replace it with my old Toshiba labtop adapter with splice Sony head to Toshiba?
If I do not use CD all the time?
November 19th, 2010 at 1:23 pm
my toshiba laptop (tablet edition)whn i start pci express error,how i can solved problem.
November 18th, 2010 at 9:17 pm
Hello… just wanna ask… i got my first laptop the toshiba L505… the problem was… I’m so confused on its power input… like the adapter above(image above) it said… input 100v-240v and the another one was the PSE info that said AC 100V 1.5a 50-60Hz… pls help im so confused… I’m still using power transformer to insure i plug it in 100v… I’m from philippines and the power voltage was 220V… the laptop was from japan and japan has 110v power voltage… pls help..
thanks you in advance….
November 15th, 2010 at 9:46 pm
David,
Just buy a new adapter, it shouldn’t be very expensive.
November 8th, 2010 at 9:11 pm
Hi,
I have a Gateway ADP-65HB BB adapter, and when I plug it in, its output reads the right voltage, but then it immediately begins to drop until it reaches zero volts within 10 seconds or so. You can easily see the power led on the adapter slowly dimming out, until it’s completely dark. Now, this is totally silly, I know, but I opened the sealed adapter case, in hoping to find an obvious damage on some easily replaceable component, but didn’t notice anything strange. Yet, I don’t have the knowledge required, so I don’t know what to look next. Could you please help me?
Much Thanks,
David
October 31st, 2010 at 11:32 am
On occassion, my toshiba ac/dc power adapter gets smoking hot.
What’s up please.
October 26th, 2010 at 5:43 am
hello.. i have a problem with my laptop.. if i going to plug the adapter without the battery it wont power on.. but if i put the battery it has a power and it is charging.. and the indicators say “AC power source (charging).. can u pls help me about this problem.. thanks a lot..
October 13th, 2010 at 7:28 pm
janet,
Normally, if your AC adapter rated 19V, the output would be very close to 19V.
9v is not normal. I think you need to replace it with a new one.
October 13th, 2010 at 6:19 pm
My adapter output is 19v but on the voltmeter it reads 9v do I need to replace it
October 13th, 2010 at 9:36 am
cad,
Probably the laptop not worth fixing.
There are no new motherboards on the market. Most of them are refurbished AND expensive.
Just put your money into a new laptop.
October 13th, 2010 at 7:00 am
yes i Did remove the motherboard and tested the voltage on the jack. thanks i guest am going to have to buy a motherboard but first sen it to a repair shop
October 11th, 2010 at 5:28 pm
cad,
How do you know the DC jack is working? Did you remove the motherboard and tested voltage on the jack?
If it’s not bad AC adapter or jack, it must be motherboard problem. Sorry cannot help here, I’m not fixing motherboards on the component level.
October 11th, 2010 at 5:18 pm
Dave,
Targus is not Toshiba AC adapter. I would suggest using original factory adapter instead of third party adapters.
Sorry, cannot answer your question.
October 11th, 2010 at 5:01 pm
Joe,
If it’s same type of connector (with same polarity), probably you can use HP adapter on Dell laptop. The voltage is almost the same and higher amperage shouldn’t cause any problem. This is my opinion.
October 9th, 2010 at 7:35 am
i have a problem my gateway mt6707 laptop will not start or charge the battery nothing will come on.i checked the adapter and its working and the dc jack is working what could be the problem ? need help plz!
October 9th, 2010 at 5:21 am
what should the resistance between positive and negative output plug in a targus toshibia power adapter. Output is 15-24V@90W max
October 5th, 2010 at 6:24 pm
Hey, I’ve sifted through all of these comments and could not find an answer:
I’d like to use an HP adapter on a Dell Inspiron 6400:
Dell’s original adapter
19V 3.34A
Hp’s adapter:
18.5V 3.5A
I have no need to charge the batter on the Dell; my main concern is whether using the power adapter could potentially be damaged by using it in the Dell. The Dell turns on with the HP adapter plugged in, but I don’t want to run it if it could damage my only adapter (I use the HP laptop normally).
Thanks.
September 7th, 2010 at 7:03 am
chelsea,
It’s hard to tell without testing even for an experienced tech.
There should be a green light on the AC adapter when it’s plugged into the wall. If the green light is off, the adapter is dead.
Also, you can test your AC adapter with a voltmeter. If it outputs correct voltage, most likely the adapter is good.
August 26th, 2010 at 7:47 am
my ac dc adapter just stopped working for my dell inspiron 1545 how can i tell if the ac part needs to be replaced or if the plug in needs to be replaced?
August 18th, 2010 at 9:08 pm
Avi,
How do you know the adapter is good? Did you test it with another laptop or used a voltmeter?
If the adapter is good but power LED doesn’t light up, there could be a problem with the DC jack.
It’s necessary to disassemble the laptop and take a closer look at the jack. If the jack is loose or damaged it has to be resoldered or replaced.
Here’s what I’m talking about: http://www.laptoprepair101.com/laptop/2007/12/06/dc-power-jack-repair-guide/
August 17th, 2010 at 8:56 am
I have a Gateway Cx200X laptop. I was travelling and one day i noticed that it isnt getting any power (power light is off). I have checked that the adapter is working fine.
What do I do now ? I am a novice with laptops, but willing to take the plunge and fix it if I can get some guidance. I searched this website for any details for steps one would follow for such symptoms. Any help would be highly appreciated.
thank you,
Avi
July 12th, 2010 at 10:04 am
jide,
Do you still have the old adapter? Find the part number and google it. This way you can find the right replacement.
July 11th, 2010 at 6:06 pm
please can someone help me i have been trying to get an adapter with with the capacity of 17 volts or 16.8 volts with 2.0 ampaere can someone help me with the store or on how i can get the adapter
July 10th, 2010 at 9:11 pm
my adapter is a 65wc-ac adapter computer and i need to know how to rest it so mycomputer quits saying plugged in not charging and it starts charging