Acer Extensa 5430 Dead Board

[Honziq]

Hello,
I got this notebook for repair.
Notebook powers on when i connect power supply and cannot turn off.
On battery it can be powered on, but not off.
When its powered on, only leds shinning, but LCD not working.
I find on board burned SMD transistor U42.
Thanks for any help.

[drdyzio]

Re: Acer Extensa 5430 Dead Board

a schematic would help
these might be it

hi res pics of the mobo would help aswell

[atsio]

Re: Acer Extensa 5430 Dead Board

How many pins on U42? Any markings - printings on the board which will help us on the board you have?

[Honziq]

Re: Acer Extensa 5430 Dead Board

a schematic would help
these might be it

hi res pics of the mobo would help aswell

Hello, here is photos of the board and detail of U42.

[Honziq]

Re: Acer Extensa 5430 Dead Board

How many pins on U42? Any markings - printings on the board which will help us on the board you have?

U42 Have 3 pins, i think it is transistor.

[Honziq]

Re: Acer Extensa 5430 Dead Board

How many pins on U42? Any markings - printings on the board which will help us on the board you have?

On this schematic i find it is mosfet.
On page 47 you can see it.

[atsio]

Re: Acer Extensa 5430 Dead Board

U42 is an APM2300AAC n-channel fet. Check voltage on all pins after pressing power button to determine if fet is bad.

[cyberhack]

Re: Acer Extensa 5430 Dead Board

Some one has heated up the gpu from what I can see in the pictures bad news.

[Honziq]

Re: Acer Extensa 5430 Dead Board

U42 is an APM2300AAC n-channel fet. Check voltage on all pins after pressing power button to determine if fet is bad.

On G is 4,52V
ON S is 0,35V.
ON D is 1,75V.

It is very hot and making little smoke when is powered on.
On battery I can turn on the laptop, but not turn off.
On AC power supply is turning on automatically, when i connect power.

[Honziq]

Re: Acer Extensa 5430 Dead Board

Some one has heated up the gpu from what I can see in the pictures bad news.

And is this the problem?
Is the mosfet connected to the GPU?

[atsio]

Re: Acer Extensa 5430 Dead Board

Replace it and check KBC

[cyberhack]

Re: Acer Extensa 5430 Dead Board

kbc is turning out to a stock fault