Netbook won't turn on

[Nico Las]

Hi, hope you can help me sort out this problem. The thing is, i have an Asus Eee PC1005PEB which, the other day, suddenly turned off. I was using it while the battery was being charged. Then, I tried removing it and leaving only the power cord connected, but nothing happened. There is no sign of life, no lights on. Nothing.I didn't smell burning either.
I tested the power supply and the readings were correct(19 v with no load),disassembled the netbook, disconnected everything( Wifi, HD chord,etc) but still it wouldn't turn on.
Finally, something strange happened. I tought the DC IN jack might be the problem(the model has 4 pins soldered to the board ). While I was doing some tests, I happened to plug the power adapter and, a few times, I noticed some sparks coming from the inside of the female jack. I realised the male plug( the one coming from the power source) suffered minor burns, nothing big. Anyway, tested it again(no load) and everything was fine. I tried to measure the voltage right on the weldings that held the female jack to the board. This is what surprised me. The multimeter kept showing nothing but 0V. If i am not wrong, the 4 pins are grounded except from the positive one. May be i was measuring it on the wrong place.
I took the notebook to a repair shop. They told me ,vaguely, "the mother shorted out". I asked for more information and the only thing i got was "It is an IC problem ".No information about the model was provided.
I was wondering if the problem might have been caused by any IC on the board.
Couldn't this be a "bad welding" jack issue?
Thank you in advance

 

[anything4this]

The motherboard did short out which caused the sparks. You must have shorted something when you disassembled it. The specific ic cant be know because now you have a burned ic and a short somewhere.. sell for parts

 

[Nico Las]

Right. That is possible, but then, what about the starting problem? I mean, the sparks and everything happened later when I was doing a few tests and connected the plug ,which I think is suspicious. Furthermore, doesn't it have a kind of protection against short circuits coming from the power source?
Thanks for your help

 

[jarotech]

Hi, the charging chip is the source of the short circuit or a transistor around this chip. Your adapter is alright until in the long run it will short itself from being connected to the laptop.

 

[Nico Las]

Im not sure I understood your whole answer jarotech, particularly when you talk about the Dc adapter.
Thanks

 

[anything4this]

Right. That is possible, but then, what about the starting problem? I mean, the sparks and everything happened later when I was doing a few tests and connected the plug ,which I think is suspicious. Furthermore, doesn't it have a kind of protection against short circuits coming from the power source?
Thanks for your help

It may have been caused by a dead IC resulting in hardware failure. Not much more to talk about because its not coming back now

 

[Nico Las]

All right then. Thank you all for your help.
So, to sum up, I should leave behind the idea of replacing, just in case, the DC IN jack and take it to the repair shop again, shouldn't I?

 

[jarotech]

If you are skillful you could replaced the DC jack, just to be sure it's not the problem. If you still have a short circuit after your repair, then the circuit charging the battery is defective.

 

[Nico Las]

I will try to do that. Anyway , shouldn't it at least power up with the DC adapter even if the charging circuit were wrong?
Thanks

 

[jarotech]

I'm sure not, because the circuit that charges the battery also controls the power of the laptop.

 

[Nico Las]

I noticed something strange yesterday. With the power cord connected , I performed a continuity test between the female jack 's positve pin and ground . The multimeter started to play beeps and then mute at constant intervals of time. This is what I find strange, because it seems like there is some component making this intermitent shorts.
I also plugged the power cord, disconnected from the adapter, to the netbook. When doing this, there is no short. The same happens when no plug is connected.
Finally, still no voltage on the DC Jack pins.