Author Topic: [Question] Laptop, power adapter and short circuit  (Read 159 times)

Offline Clannad_92

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[Question] Laptop, power adapter and short circuit
« on: March 10, 2017, 03:00:00 pm »
hi all, got a simple questions; what are the effects of using different power adapter let say;

asus x451ma
- original adapter 19v 1.75a
- "replacement" adapter 19v 3.42a (currently using or should i say, used)

and related to above question, can that "replacement" adapter shorted motherboard? ive checked the "replacement" adapter and got current leak (test pen lights up), as the laptop now doesnt turn on

thanks

Online kitamesume

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Re: [Question] Laptop, power adapter and short circuit
« Reply #1 on: March 10, 2017, 04:56:43 pm »
is the original DC or AC? the same question to the replacement.

also test whether the replacement is actually putting out 19v and not any other voltage.

Offline Mistgun_Zero

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Re: [Question] Laptop, power adapter and short circuit
« Reply #2 on: March 10, 2017, 05:52:17 pm »
No. As long as the voltage is correct (voltage is basically the electrical pressure aka potential, this is the main criteria in most cases in terms of compatibility), current rating has a lesser impact. The 3.42 A current ratings means the adapter can give an output of 3.42 A maximum. It will only supply as much as required by your computer. But, make sure it is a quality product and it does indeed output 19V. Easy with a multimeter. Should not be a problem.

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Offline Clannad_92

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Re: [Question] Laptop, power adapter and short circuit
« Reply #3 on: March 10, 2017, 06:32:05 pm »
so, the current rating will not affect the laptop?

...can that "replacement" adapter shorted motherboard? ive checked the "replacement" adapter and got current leak (test pen lights up)...

Offline Mistgun_Zero

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Re: [Question] Laptop, power adapter and short circuit
« Reply #4 on: March 10, 2017, 06:49:17 pm »
^No, of course not. Like I said, current rating only indicates the maximum it can supply, not what it will. The supply will depend on how much your laptop asks of it. So, yes, you are safe and your system won't be short-circuited.

FYI, short circuit means when there is a direct connection between positive and negative terminals of a power source. A higher rating will never be the cause of short circuit. (it might result in over current, but don't worry, it's not gonna be a problem in your case).

Homu-Homu is troubled

Offline Clannad_92

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Re: [Question] Laptop, power adapter and short circuit
« Reply #5 on: March 10, 2017, 07:19:26 pm »
so how about this, disregarding the current rating;

...can that "replacement" adapter shorted motherboard? ive checked the "replacement" adapter and got current leak (test pen lights up)...

sorry for asking a lot of question, but you know the moment when your brain goes "how the universe works" before sleeping.

Online kitamesume

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Re: [Question] Laptop, power adapter and short circuit
« Reply #6 on: March 11, 2017, 12:32:29 am »
so how about this, disregarding the current rating;

...can that "replacement" adapter shorted motherboard? ive checked the "replacement" adapter and got current leak (test pen lights up)...

sorry for asking a lot of question, but you know the moment when your brain goes "how the universe works" before sleeping.

answer these questions first...


is the original DC or AC? the same question to the replacement.

also test whether the replacement is actually putting out 19v and not any other voltage.


because answering it literally answers 99% of your questions, besides fixing the problem itself.
« Last Edit: March 11, 2017, 12:36:01 am by kitamesume »

Offline Clannad_92

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Re: [Question] Laptop, power adapter and short circuit
« Reply #7 on: March 11, 2017, 02:09:45 am »

is the original DC or AC? the same question to the replacement.

also test whether the replacement is actually putting out 19v and not any other voltage.

AC to DC, but why did you ask this? arent all pc uses AC to DC adapter?

and yes, it did 19v

Offline Mistgun_Zero

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Re: [Question] Laptop, power adapter and short circuit
« Reply #8 on: March 11, 2017, 03:17:41 am »
is the original DC or AC? the same question to the replacement.
also test whether the replacement is actually putting out 19v and not any other voltage.
Ummm.....no? All the laptop inputs are DC. There is no AC input for any computer stuff. What you get is a standard 110v/220v AC (for connectino at the socket) to DC adapter (the output that goes into a computer).

@Clannad: Of course, the test pen is gonna light up, since you are checking if there is any supply and it is showing just that. There might also be a problem with the motherboard itself, of course, but that's a totally different thing.


because answering it literally answers 99% of your questions, besides fixing the problem itself.

Homu-Homu is troubled

Offline Clannad_92

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Re: [Question] Laptop, power adapter and short circuit
« Reply #9 on: March 11, 2017, 03:39:22 am »
@Clannad: Of course, the test pen is gonna light up, since you are checking if there is any supply and it is showing just that. There might also be a problem with the motherboard itself, of course, but that's a totally different thing.
really, if that is, then why does my power adapter doesnt lights up(test pen) ? that "replacement" adapter does lights up(test pen)

if my memory doesnt betray me, i faintly remembered that some educator tells me that test pen also can check for leak current

Online kitamesume

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Re: [Question] Laptop, power adapter and short circuit
« Reply #10 on: March 11, 2017, 04:07:26 am »

is the original DC or AC? the same question to the replacement.

also test whether the replacement is actually putting out 19v and not any other voltage.

AC to DC, but why did you ask this? arent all pc uses AC to DC adapter?

and yes, it did 19v
because i have a few power bricks which outputs AC, if you plug that on a DC input laptop the laptop's input filters will short circuit.




really, if that is, then why does my power adapter doesnt lights up(test pen) ? that "replacement" adapter does lights up(test pen)
because the original is probably dead, the new one is working as intended.
test pen functions as an indicator whether "it works or not", if it lights up it works, if not then its dead.


if my memory doesnt betray me, i faintly remembered that some educator tells me that test pen also can check for leak current
define "leak current", e.g. what are you expecting to leak?
if you're saying the AC supply is leaking through the output, then it can be tested with a voltmeter set to AC.
or rather, you can test it by touching the output terminals with your bare hands, if it tingles then theres a problem.
« Last Edit: March 11, 2017, 04:55:38 am by kitamesume »

Online jevitsj

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Re: [Question] Laptop, power adapter and short circuit
« Reply #11 on: March 11, 2017, 08:52:15 am »
If it's DC, then this is also important, the replacement needs to have the same polarity as the original:

Online kitamesume

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Re: [Question] Laptop, power adapter and short circuit
« Reply #12 on: March 11, 2017, 10:29:32 am »
ah yes, i forgot about that, i've also have bricks with a polarity switch, you can choose for either.

Offline Clannad_92

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Re: [Question] Laptop, power adapter and short circuit
« Reply #13 on: March 13, 2017, 07:53:52 am »
really, if that is, then why does my power adapter doesnt lights up(test pen) ? that "replacement" adapter does lights up(test pen)
because the original is probably dead, the new one is working as intended.
test pen functions as an indicator whether "it works or not", if it lights up it works, if not then its dead.
my adapter is alive and in service but no lights when tested with test pen, the "replacement" adapter is alive but lights up when tested with test pen

so, with my current knowledge, the "replacement" adapter current is leaking

Quote
define "leak current", e.g. what are you expecting to leak?
if you're saying the AC supply is leaking through the output, then it can be tested with a voltmeter set to AC.
or rather, you can test it by touching the output terminals with your bare hands, if it tingles then theres a problem.
yep, tingling sensation, sometimes with stonger version

on phone atmatm, sorry