Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

[doros88]

I have a UX330CA Rev 2.0 motherboard (Asus)
NOTE: Led Flashes White for 1 Short (Gives V+) , 1Long , 1 Short (Give V+)
then Nothhing !
DC–in MOSFETS measure ok ! no shorts ! 3.3V and 5V coil show for the duration of Led Flashing.
3.3V Coil to ground -> 14 K ohm
5V Coil to ground -> 16K ohm
BQ24780S
VCC -> 19V stays
RGEN -> 6V stays
ACOK -> 5V for the duration of Led Flashing
ACDRV -> 24V for the duration of Led Flashing
ACN -> 19v fluctuates to 3.7V for the duration of Led Flashing , Then drops to 0V
ACP -> 19V fluctuates to 3.7V for the duration of Led Flashing , Then Drops to 0V
PHASE -> Fluctuates from 0.8V to 0.250V for the duration of Led Flashing (then stays to 0.150V)
BTST - > 5.899 V
CMSRC - > Fluctuates 18.4V to 0.0360V then stays to 0.0360V finally drops to 0V
ACDET - > 2.5V <- 1st Flash 2.6V second Flash then stays at 1.890V
SDA - > 3.3V Fluctuates to 0.1870 then 0V
SCL - > 3.3V Fluctuates to 0.1870 then 0V
Need Help trouble shooting the Board !
Thanks in Advance !

[mon2]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

Remove all power; meter in resistance mode.

Measure the DCin mosfets and post their readings so we can review if they are defective or not.

The resistance should be high across the pins if they are ok.

Other charger values look ok.

Using the original charger?

[doros88]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

Thanks for the quick Response !
It's not the original charger ! A dc jack that i hook on to my lab power supply
The Board needs 19V 2.37A !
I will do that
.....................
So i measure the 2 DC-in Mosfets
E180AJ (1st mosfet)
Diode measure 0.4V Source (+) Drain (-)
In reverse OL

D-S 1.8 Mohm
G-D 1.08 Mohm
G-S 1.72 Mohm
A5GNB (2nd mosfet)
Diode measure 0.5 Source (+) Drain (-)
In reverse OL
D-S 5.7 Mohm
G-S 2.08 Mohm
G-D 4.5 Mohm

[mon2]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

Mosfets are with good readings.

Remove all power. Measure the resistance to ground of the main power rail which will follow after the 2nd mosfet.

It is the one that is pulsing to ~3v from 19v.

Perhaps a bad cap on the main rail ?

What is the resistance to ground?

[doros88]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

I measuring now It start from 1.5 Mohm and i am at 5.1 Mohm and still climbing (slower than in the beginning ) i put my lead after the 2nd mosfet just before 10mohm current resistor !
Thank you for helping me !Learning a lot just by reading cases here and from you guys !

[mon2]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

I have not searched but any chance you have the schematics for your logic board? I think I have the boardview file in my database but can confirm in another hour or so. We are doing pcb production today and the machinery needs nursing. Also training my son, the next generation of pcb assembly.

[doros88]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

Unfortunately no.I search the "whole internet " for Schematics and boardview but nothing !Sorry for the time taking from you ! I am happy for the quick response ! When you have the time ! no worries ! its already amazing that i have someone to explain and help me with this ! Any ideas? its not the BQ24780S ?

[mon2]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

I see only UX330UA boardview files in my database

Some component on the logic board is supplying the blink pattern but not 100% clear if this is the KBC controller which has an internal microcontroller (often the 8051) or if the main CPU is involved.

It may be worthwhile to hunt down what this blink pattern means for the Asus motherboards.

If the RAM is removable -> remove it and see if the blink pattern changes or not.

Otherwise, proceed to check the voltage on each large coil (inductor) which will be linked to a local power supply regulator.

Do you have such coils with 0v or very low voltage when the unit is powered ON ?

If yes, then REMOVE all power -> meter in resistance mode -> check the resistance to ground of that same coil. Post the resistance reading. That coil may be with a low resistance due to a bad cap (shorting).

[doros88]

Re: Asus UX330CA Rev2.0 1Short1long1Short 19V No Power

Cannot remove the RAM.(D9TDZ) The SuperIO (ithink) is ITE IT8995VG-128.
i attach a pic of the board with the Measured Voltages and resistance to the ground.
Next to the 2 coils (the 57 ohm and 100 ohm) is APW6002 which i didnt find datasheet.
Also i cannot find the Datasheet for SuperIO ITE IT8995VG-128 so i cant measure any voltage or signals!
Thanks Again !