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mike[_22_]

On 5/11/2018 6:35 AM, wrote:
On Friday, 11 May 2018 07:19:02 UTC+1, mike wrote:
On 5/10/2018 11:14 PM, tabbypurr wrote:
On Friday, 11 May 2018 04:41:46 UTC+1, Python Studios wrote:

I was watching a youtube video when I realized that my ac/dc adapter was unplugged from the wall and grounding unit. I plugged it back in and my laptopl froze then made a loud buzzing sound. I imeditaly turned it off and on, there were 0 probelms. Then, when I made sure that my power cord was working, I plugged it in and nothing. When I remove it, the screen flashes black for about 1/5 of a second this is only external. I don't know if my adapter has been fried or the power component in my laptop has been. I am rushing this post because I only have 17% left on my latptop and this is the only device I have. I am backing up everything and I also ran power diagnostics. Please, if you have any information on how to check if one is broken or the other, respond immeditally. Sorry for the bad post, but time is limited. Tomorrow, I am going to try and build a charger (usb) for it with some extremely low output batteries and capacitors 130maH in total.
yes, I am on it now for those of you who are "slow".

a multimteter will tell you what's coming out of the psu.

It's hard to get a connection to the interface between the PS
and the computer when it's plugged in.
Measuring the PS unloaded can tell you if it's dead, but not
much else.
junk snipped

It's the first thing I'd do. What's the first thing you'd do?

NT

That's the first thing I'd do too.
BUT
If it measured the correct voltage, I'd put a load on it
and look at it with a scope.
This is FAR EASIER than taking the laptop apart, only to find
that the AC adapter was bad all along...and you broke a bunch
of the plastic snaps trying to pry it apart.
Been there, done that.

Make DARN sure the power supply is good before disassembling
a laptop.

In ANY diagnostic situation, you start asking questions to determine
the diagnostic tree. For each question, ask yourself, "What am I
gonna do with the answer once I have it?" If you can't do anything
with the answer, it doesn't help to ask the question. You can lop
off whole branches of your diagnostic tree. If your lack of test
equipment lops off ALL the branches, you're dead in the water.
Fixing it will be a matter of luck.

In this case, if you can't load the power supply and look at it with
a scope, you have two options.
1) output voltage is not correct on the multimeter. laptop ac supply
is probably defective.
2) no load output voltage is correct...and you don't have a scope you
probably shouldn't be taking the laptop apart until you have more info
or a known-good power supply.

"my laptopl froze then made a loud buzzing sound" is NOT a good symptom
That it didn't buzz next time suggests like the power supply is defective
and it blew a fuse or something inside the laptop.
Or that a static zap killed it when it was plugged in.
OR...OR...
In that case, trying a good power supply may not fix it.
And if you fix the inside problem and plug in the bad supply,
you may break it again.
Been there done that.