Asus X550JX rev 2.0 not power on !

[lapfix]

Hello friends
Got this motherboard with ram buit in that didn't power on : Asus X550JX rev 2.0

No short to GND At all coils.

When i connect charger cable ( from power supply ) the lap is on , consumption is going from 0.03 to 1.8 ( with fluctuation = 0.6/1.2/1.6/1.8 ) for second than back to 0.03.

All voltages are presents when she's on for this second.

Try anothers bios same issue. changing bios chip same issue too.

RSMRST IS OK...Plt_rst is present..

The only thing that i notice is : Pwr_sw at pin 110 U3001 = = 0.133 v ! it must be 3v

Also Pwr_sw is = 0.133v at D3201 pin 3
All others voltages at D3201 are present.

Tracing Pwr_sw from pin 110 to a resistance = R3037 100Kohm...find 3Va from one side but from the side of io is 0.133v...changing resistance still same issue .

What i miss...what to check else !...thank you

[mon2]

Re: Asus X550JX rev 2.0 not power on !

1) Unable to locate D3201 in my Rev 2.0 schematic of the same.

2) R3037 is also mated with C3010 capacitor to form a RC power on circuit. Check on the condition of C3010 or even consider to desolder this part for testing. After this cap is removed, what is the voltage on PWR_SW# ?

It should be pulled to ~3v due to R3037 function.

[lapfix]

Re: Asus X550JX rev 2.0 not power on !

Thank you mon2
sorry i mean D6201 (D3201 is at another donar board)
C3037 is not populated at this motherboard

It should be pulled to ~3v due to R3037 function = yes i know that's why i change it but still same issue

Even if i join the 2 pads of R3037 with twizer and get 3 v at pin 110 io and pin 3 of D6201..not power on

[mcplslg123]

Re: Asus X550JX rev 2.0 not power on !

Seems like bad SIO. Not sure though.

[mon2]

Re: Asus X550JX rev 2.0 not power on !

Ok. See attached.

There is no D6201 inside my schematic for Rev 2.0 for the logic board.

There is a D6201 inside the Rev 2.1 schematic.

Remove all power. Meter in resistance mode (lowest scale).

Check the resistance to ground with one meter probe on

PWR_SW#

and the other meter probe to ground.

What is the resistance reading in ohms ? Also post the meter scale used for the measurement.

[lapfix]

Re: Asus X550JX rev 2.0 not power on !

Ok
my board is Rev 2.0 but i use 2.1 BRD.
I use automatic range , so just put my meter scale at the ohm signal ( am i right ! )

pin 1 = lid_sw = 156 kohm
pin 2 = GND
pin 3 = pwr-sw = 3.530kohm
pin 4 = pwr_led = 08.40mohm
pin 5 = +3Va_ec = 289.6kohm

[mon2]

Re: Asus X550JX rev 2.0 not power on !

Using flux & hot air, remove the ESD device @ D6201. Make a note of the orientation of this device for replacement after this test.

Then measure again the resistance to ground for pin # 3. Post the reading.

[lapfix]

Re: Asus X550JX rev 2.0 not power on !

same = 3.530kohm

[lapfix]

Re: Asus X550JX rev 2.0 not power on !

When i change R3037 ( 100Kohm ) , whent measure at the donar board i find 96 kohm..so it's ok but when soldered at this board and measured = 60kohm.

Seems like bad SIO as mcplslg mention before !!

[koby058]

Re: Asus X550JX rev 2.0 not power on !

what is SIO ?

[mon2]

Re: Asus X550JX rev 2.0 not power on !

Attached.

[koby058]

Re: Asus X550JX rev 2.0 not power on !

So this one can be replaced, yes? or it is programed?

[mcplslg123]

Re: Asus X550JX rev 2.0 not power on !

When i change R3037 ( 100Kohm ) , whent measure at the donar board i find 96 kohm..so it's ok but when soldered at this board and measured = 60kohm.

Seems like bad SIO as mcplslg mention before !!

This is not the way to conclude. A resistor will not show its actual value when soldered on board. I'll suggest to apply flux and warm the sio pins slightly to see if it makes any difference. ON some asus, power switch is powered by RTC circuit. So do check whether there is any issues within RTC circuit. last option is to replace the SIO.