asus x55A no power

[ktmmotocross]

Hello.
Have this asus X55A and i have 19V before the first power mosfet and 0.89V after the mosfet.

i cannot find schematic so any help would be needed

[dj_ricoh]

Re: asus x55A no power

find the qfn chips!

model and see what they do.
first is first did you find any fets broken or caps?

[ktmmotocross]

Re: asus x55A no power

i measure the charger ic bq24725

[polytek]

Re: asus x55A no power

maybe this can help you;

[ktmmotocross]

Re: asus x55A no power

already have it but its totally different hw

[ktmmotocross]

Re: asus x55A no power

when i inject 19V to base of first mosfet system works. there must be something that prevents ic to launch full 19V signal to that mosfet.

charging led is on but no voltage goes to battery, but i dont know the life of battery

[dj_ricoh]

Re: asus x55A no power

Swap then.
That ic opens with gate the fet for battery and adapter.

[polytek]

Re: asus x55A no power

i agree to dj_ricoh, try to swap these mosfet

[ktmmotocross]

Re: asus x55A no power

mosfet is good. ricoh means swap ic

[Claudio Silva]

Re: asus x55A no power

Hello.
Have this asus X55A and i have 19V before the first power mosfet and 0.89V after the mosfet.

i cannot find schematic so any help would be needed

Hello friend.
That means your second PQ´s not activating, the first Mosfet is a Díode Mosfet and it doesn´t need the voltage on gate to activate, i may need 0v on pin 4 of second Mosfet to activate.


It looks like you don´t have +/- 6V gate sinal on second PQ.

[ktmmotocross]

Re: asus x55A no power

i order some of these charger is because 5 laptops with DDR3 IN A ROW have bad this ic.

or if customer wont pay for replace i just inject 19V to ACDRV signal rail to have system work but without battery and charger.

[Claudio Silva]

Re: asus x55A no power

i order some of these charger is because 5 laptops with DDR3 IN A ROW have bad this ic.

or if customer wont pay for replace i just inject 19V to ACDRV signal rail to have system work but without battery and charger.

I´d inject 6v to 9v on second PQ, that´s a PNP Mosfet injecting 19v may be too high.

[lorins_core]

Re: asus x55A no power

find the qfn chips!

model and see what they do.
first is first did you find any fets broken or caps?

may i know the qnf?

[Claudio Silva]

Re: asus x55A no power

may i know the qnf?

What is a QFN?

[cyberhack]

Re: asus x55A no power

This is it QFN quad-flat no-leads
The bit that controls the charging/ input chip

[Claudio Silva]

Re: asus x55A no power

This is it QFN quad-flat no-leads
The bit that controls the charging/ input chip

Thanks for your answer, but can you please explain a bit more?
QFN is a enable pin that turns on or off the Charge IC?

[emr2000]

Re: asus x55A no power

my computer does not come apart in wolt. 3v 5v I can not. I changed ıt8517. I changed the bq25. still no wolt

[Djosla]

Re: asus x55A no power

I find second mosfet ,from dc_in konektor, shorted almost always...

[risting]

Re: asus x55A no power

you fixed you laptop ?
I have the same similar problem

[risting]

Re: asus x55A no power

i have asus x55A
my laptop completely is dead not even one LED all is off What is broken on my laptop
can someone help me