Acer 5520 laptop is acting weird

Hello there, I've been having some problems with my laptop.
I searched a lot about what could be wrong with it, but couldn't find the right answer, so I finally decided to ask directly.

The main issue is that my laptop turns off suddenly. It works for some minutes but If I open some program or search in the internet, etc, it goes off without a warning.
Sure, I did some cleaning, I opened the laptop and cleaned the fan and heatsink. All goody. But that wasn't the problem, two blue screens already appeared and both mentioned something about the Hardware and BIOS.

Apparently my computer looks okay, I can't see anything wrong, other than the "power off" thingy.

I really need help, I'm tired and my anger towards this laptop is too much x)
Also, I don't know if it helps but this computer has been shut down for almost a year or something, because my sister got some viruses and the computer started shutting down. That's when it started, I just got to it now because I really need it... yeah

I hope someone can gimme a little help in here, Thanks

 

Check if it's overheating using software like HWMonitor, RealTemp etc.
Have you re-installed Windows since the virus incident?

 

I wouldn't be surprised if it were Bumpgate - the 5520's northbridge is badly affected.

 

Hello

@Downloads;well I doubt that "overheating" is a problem, because the laptop doesn't get hot nor anything, but because I'm not an expert it could be xD
I'll use that to see if it really is.
As for the windows installing, yes.

@.NetRoller3D; I'm not sure what that is. I'll have to search then. But if that could be the problem, what can I do to fix it?

Sorry for the english and technological terms.

 

Update:

I downloaded HWMonitor through the safe mode. Got into normal mode and this is what appeared in the program:
(Not sure if it helps)
___________________________________
Acer Fuquene
-THRM value(45ºC) Min(45ºC) Max(55ºC)
AMD TURION 64 xz Mobile TL-58
-Core#0 Value(39/40ºC) Min(39ºC) Max(52ºC)
-Core#1 Value(39/40ºC) Min(39ºC) Max(53ºC)
WDC WD2500 BEVs-22USTO
-Assembly Value(33ºC) Min(33ºC) Max(33ºC)
...
_____________________________________

It just gave me time to write those down, then it shut down, I took a glimpse at the core temperature and instead of 40ºC it was like 56ºC when the computer turned off.
I'm not sure, but I don't think it's overheating.


As for the northbridge matter, I searched about it and still don't get what it is, from what I've read it is something about a fan and a drive?

I'm lost here.

 

It's definitely not overheating.
If .NetRolller 3D is right you may end up trying to do a home-made reflow or buying a new mobo.

 

I knew it!
I had hoped that my laptop's problem would be minor so that I didn't have to spend money nor much time with it, but I guess that's impossible xD
My father has a friend that knows his way around computers and has fixed my other computer many times, I'll send this one to him as well to see what's the real problem, etc.

Thank you for the help