Acer Aspire 5742g turns off but I´m able to enter bios

azigta

Estimable
Oct 23, 2014
3
0
4,510
Hi, I reciently got problem with an acer aspire 5742g. It turns off when trying to boot from cd or usb.

I thought it could be a temperature problem so I read on internet about desoldering the motherboard cmos battery for half an hour and placing it back on. I did that.

I also replaced the thermal compound on both cpu and graphics card.

The laptop stills shutting off. I can access bios with no problem, but if I try to boot from cd or usb it just turns off

I updated the bios from version 1.07 to the latest bios wich is 1.30 succesfully, but the problem persists.

Also, recently, the brightness dropped down and I can´t do a thing to solve that...

I think this is a motherboard problem... Has anyone got an idea of what component of the motherboard could be in bad condition? I´m an electronics student and I usually repair motherboards with visible damage (including smds etc.) but with no visually damaged components I don´t have a clue of what is the component that might be causing this.

Is this a common problem? How is it possible to be able to get in the bios but not boot? Untill I try to boot I´m able to access the bios but after that I have to do a discharge of the laptop to be able to access it. It doesn´t make any sense to me. Does anyone know what could be the issue? I´m lost!
 
Solution
Other than the obvious (caps, discolored or blown IC's etc.) I'm at a loss for where to go here. I'm thinking 5v voltage regulation is wonky (or completely shot) which would likely be a very small IC (or more than one). Concentrate around the voltage regulation area is all I can suggest here

azigta

Estimable
Oct 23, 2014
3
0
4,510



Yes, I did check the battery, it was a little above 3v
 
Other than the obvious (caps, discolored or blown IC's etc.) I'm at a loss for where to go here. I'm thinking 5v voltage regulation is wonky (or completely shot) which would likely be a very small IC (or more than one). Concentrate around the voltage regulation area is all I can suggest here
 
Solution

azigta

Estimable
Oct 23, 2014
3
0
4,510


thanks for the suggestion. I´ll look