Asus Gaming FX553V No power

[eng.jaudat]

Hello, i'm trying to fix Asus Board
Model of the Laptop is: FX553V
MB: (GL553VD Rev:2.0)
when i check the mosfets power i found the second one is dead.
after i changed it the mobo still not working.
the first power mosfet not pass the 19V, and there is no voltage on the gate.
how i can know the reason of loss the voltage in the first and second mosfets gate?
i'm searching for the schismatic but can't found it any where on the web

[ktmmotocross]

Re: Asus Gaming FX553V No power

check charging ic pins for voltage and compare it to datasheet

[leone0310]

Re: Asus Gaming FX553V No power

Check for shorted cap after the second fet.

[eng.jaudat]

Re: Asus Gaming FX553V No power

thanx pro,
i can't found any data sheet for this mobo online.

BQ735 is the charging ic?

[eng.jaudat]

Re: Asus Gaming FX553V No power

Check for shorted cap after the second fet.

i'm trying that using my power supply, there is no rise on the amps. so i guess there is no shorted cap.
but i will be sure using my multimeter again

[eng.jaudat]

Re: Asus Gaming FX553V No power

BQ735 is the charging IC, by reading the data sheet of it i must read 19V come directly from the DC jack to that ic. i can read just 2.45V.
is that normal?
please excuse my rare knowledge. i'm still beginner.

[SMDFlea]

Re: Asus Gaming FX553V No power

Boardview at post# 3 https://www.badcaps.net/forum/showth...hlight=GL553VD

Change the first mosfet as well.

[ktmmotocross]

Re: Asus Gaming FX553V No power

i'm trying that using my power supply, there is no rise on the amps. so i guess there is no shorted cap.
but i will be sure using my multimeter again

NEVER DO IT!!!

if u have shorted some of high side fet u will kill CHIP or whole mb

[eng.jaudat]

Re: Asus Gaming FX553V No power

REALLY!!
i just do it on the first and second mosfets. to know if there is a cap shorted in the mobo.
honestly its a very useful way, and helping me in so many dead mobo.

[eng.jaudat]

Re: Asus Gaming FX553V No power

Boardview at post# 3 https://www.badcaps.net/forum/showth...hlight=GL553VD

Change the first mosfet as well.

thank you so much, i will read it so carefully.

and i will try to change the first mosfet. but you don't thing that my problem in BQ735?? as there is no voltage in the gate of the first mosfet?

[SMDFlea]

Re: Asus Gaming FX553V No power

Probably is BQ735, its always better to change the two mosfets together,even if one is tested working.

[eng.jaudat]

Re: Asus Gaming FX553V No power

Probably is BQ735, its always better to change the two mosfets together,even if one is tested working.

can i use BQ737 instead of BQ735??

[on/off]

Re: Asus Gaming FX553V No power

can i use BQ737 instead of BQ735??

No.

Both IC have different pin out

[mcplslg123]

Re: Asus Gaming FX553V No power

Most likely some fet or cap is shorted. Did you checked resistance to gnd on B+ line. there should be a resistor just after 2 dc in fets and on that you can check resistance to gnd. You can remove that resistor and then apply power and see if 19v reaches on those pins of fets where you were not getting any voltages.