Asus X54UVK Rev 2 won't turn on

[speggio91]

Hello, this time i am fighting with a laptop motherboard that initially didn't turn on at all, completely dead.
After inspecting it, I found a shorted capacitor, for those who have the boardview, the code is C5564.
After removing that and powering the board, the red charging led turns on and there seem to be life around the board. I poked with the multimeter some inductors but there are few of them that doesn't have any voltage.
The voltages that are presents are 3.3V on inductor PL80701 and 5VSus on inductor PL8702. Also 1.0Vsus is present

The current that the board draw in this state is 20mA

When i try to press the power button, the power led lights up but after a second both leds turn off and then only the red led stays on. The board goes to protection i think, something is still not good.
During this stage the amperage peak is roughly 220mA until the board shuts down.

I have the boardview but I don't know where to continue searching.
So far I've tried to sense the voltages on the Charger manager IC PU8901 and all the voltages are present (P_CHG_ACOK, etc)

The part of the board that doesn't have any voltage is the double phase cpu power supply, the one with the mosfets PQH9103, PQH9101 etc. The 19 volt arrives but there is no voltage at the gates.

Also there is no voltage on the inductors PL9301, PL8600, PL8101 8102

On the battery charger connector I sensed 12V and when the battery is connected the voltage drop and it doesn't seem that the battery is being charged. On the mosfet PQH8901 I sense 19 coming in and 12V coming out and on the next one (PQL8901) 12 Volts coming in but 0 coming out with zero voltage at its gate.

Could be that power charger IC that I already checked to be faulty?
What or where should I check?
Any hints are very appreciated.

[Techtiger]

Re: Asus X54UVK Rev 2 won't turn on

uplode the bordview check the RTC setion and SIO requirements

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

uplode the bordview check the RTC setion and SIO requirements

Here is the boardview file:
https://drive.google.com/file/d/1Vd4...CKepwdKYX/view

here is the software for opening it:
http://boardviewer.net/


Thanks for the hints, sorry for my poor knowledge but where is the rtc section?
Sio requirements are found it the sio datasheet?

Thanks

[Techtiger]

Re: Asus X54UVK Rev 2 won't turn on

voltage on (for the RTC section) JRST2401 JRST2402 ? SIO U3001 IC pin 96 111 56 14 befoure pressing PWRBTN and after pressing the PWRBTN voltage ?

[mcplslg123]

Re: Asus X54UVK Rev 2 won't turn on

@techtiger, as per post#1, RTc issue is unlikely. Mb is trigerring with consumption of 0.220A. Problem is no VCore perhaps. Should check ram requirement and presence of all rails specially 1.8V rail.

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

voltage on (for the RTC section) JRST2401 JRST2402 ? SIO U3001 IC pin 96 111 56 14 befoure pressing PWRBTN and after pressing the PWRBTN voltage ?

JRST2401 and 2402 have both 3.2 V

U3001 IC before PWRBTN press:
pin 14= 3.3
Pin 56= 3.3
Pin96= 3.3
Pin 111= 3.3

After pressing PWRBTN (at the same time that both led power on and amperage goes to 220mA):
pin 14= 3.3
Pin 56= 0 then it rise up again at 3.3 when the board reboot
Pin96= 0 then it rise up again at 3.3 when the board reboot
Pin 111= 3.3

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

@techtiger, as per post#1, RTc issue is unlikely. Mb is trigerring with consumption of 0.220A. Problem is no VCore perhaps. Should check ram requirement and presence of all rails specially 1.8V rail.

1.8V is not present, where should I check for clues? just following the rail towards the power supply that generate that voltage?

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

Sorry I correct myself, only 1.8VSUS and 1.8 VSUSO is present

Also, VCCORE is not present and checking the voltages at pin 23 of PU8001 there is no voltage to drive the mosfet gate. Then, i've checked pin 13 and VCC 20 is present and it's 5V.
I probed pin 51 (VCCGT VCCSENSE) and it's 0V. Capacitor Pc8007 has 8 ohm resistance.

[mcplslg123]

Re: Asus X54UVK Rev 2 won't turn on

Ask for a bios in bios request section and flash bios first. If there is no changes, we'll try to troubleshoot further. Remember, to backup your bios before flash.

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

Ask for a bios in bios request section and flash bios first. If there is no changes, we'll try to troubleshoot further. Remember, to backup your bios before flash.

I did it, but I don't understand if the bios has been flashed correctly or not because after doing that the board power consumption on idle decreased at 10ma and the red charger led doesn't light up anymore.
When i press the power button nothing happen, no power and no amperage drawn.

here is the topic about it:
https://www.badcaps.net/forum/showth...67#post1041267

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

Hello,

I give you a quick update. I purchased a new programmer and successfully flashed the bios.
The problem of the board sadly is still there, nothing has changed, the red light is on and when powering the board after 1 second it shut off

What else should I check before giving up? I know I should try by myself and report more useful data but I am lost and don't know what to look for.

Any help or hint is appreciated.

[mcplslg123]

Re: Asus X54UVK Rev 2 won't turn on

Check D5801/5802/5806 for powergood signal.

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

Check D5801/5802/5806 for powergood signal.

I've checked D5801 for 1.2_PWRGD but is not present
I've also checked all the other Diodes voltages but only the 3VSUS_PWRGD is present on the pin 1 of D5802
then i checked pin 10 of PU8600 and the voltage is still not present
i checked if the ic has the required voltages and here are the only pins with a voltage:

pin9=18.30V
pin12=5V
pin18=4.7V

When pressing the power button the voltage 1.2 PWRGD goes to 3.3V for a fraction of a second the return to 0V

All the three diodes D5801/5802/5806 are fine.

I've noticed a missing component, J5901, it seem that it has been knocked off or maybe it wasn't there at all, but i see that on the soldering pads there are the ic leg footprint. I don't think it's vital for the board, it seem more part of the lid circuit to the super I/O. correct me if i'm wrong.

Could be the ic PU8600 failed? for what I saw, there seem to be power coming in but it's not providing supply to the Ram section.
The IC datasheet state this for pin 10: "Power good open-drain output. In high state when VDDQ output voltage is within the target range." Does it mean that if VDDQ is not present or not in the accepted range, the voltage won't come out from pin 10?

[mcplslg123]

Re: Asus X54UVK Rev 2 won't turn on

PU8600-It must have enable on pin7(S3 which enables VTT) & pin8(S5 which enables VDDQ) for the IC to give output. Pin9 is TON-Timer ON. It should be connected with a resistor of high value, usually 500-600K on which you should get 19V at one end and the other end of resistor will be 0.9V approx. So do check the resistor connected to pin9. You should'nt get 19V at pin9 and correct value will be close to 0.9V. In my experience, Asus mb almost always give clues for repair from missing PowerGood signal.

The enable on pin7-8 will come up only after switching on as you are aware.

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

PU8600-It must have enable on pin7(S3 which enables VTT) & pin8(S5 which enables VDDQ) for the IC to give output. Pin9 is TON-Timer ON. It should be connected with a resistor of high value, usually 500-600K on which you should get 19V at one end and the other end of resistor will be 0.9V approx. So do check the resistor connected to pin9. You should'nt get 19V at pin9 and correct value will be close to 0.9V. In my experience, Asus mb almost always give clues for repair from missing PowerGood signal.

The enable on pin7-8 will come up only after switching on as you are aware.

Thank you for the clue! It seem like the resistor PR8607 is faulty.
I've measured its voltage to ground on both sides and in fact one side its 19.3V and the other is 18.3V

The odd thing is that I've measured its resistance even after desoldering it and it's 621KOhm which is the correct value!
How is it possible that it's not lowering the voltage?

I've tried to put a resistor from another board with higher resistance, 887K.
The result is that the voltage from the IC side its 17.6V

Did I have to probe the ground from the IC GND? I did pick a random ground point on the board

[speggio91]

Re: Asus X54UVK Rev 2 won't turn on

UPDATE:

I've replaced PU8600 with a RT8207MZQW took from another board..the specs seemed to be similar to the RT8248AGQW

After replacing it and giving back power to the board, the red light is off but the white led is on.

At the side of PRD8607 and on pin 9 of the IC i sense almost 0V, few millivots.. no good.
The IC gets instantly hot and there's no power again, I can't either turn on the board because nothing happen when i press the power button, there is the power white led always on.

UPDATE 2:

After checking again I realized that I soldered the ic in the wrong orientation

After rotating it in the correct position, the voltage on pin 9 is 17,5V, I guess I damaged it and now is dead

The voltages in pin 7-8 are 3.3V now but the white led power is still on and the board is not turning at the button press.

We were so close to a potential fix and I've messed up pretty bad.

Should I try to replace the IC with another one, do you think that is the issue with this board?

Thank so much for your support!

[SMDFlea]

Re: Asus X54UVK Rev 2 won't turn on

Similar is not the same as being the right part for the job. Only the RT8248AGQW should be used (or a pin to pin equivalent part from another manufacturer,if available). Check the pin description of both datasheets carefully and you`ll see why. I hope you havn`t done more damage to the board - https://cdn.badcaps-static.com/pdfs/...5bb8a28d1e.pdf

[mcplslg123]

Re: Asus X54UVK Rev 2 won't turn on

@speggio91, yes you did make a mistake by replacing it with another ic and that too with wrong orientation. Hopefully, nothing should be damaged as mb didnt turned up. So go as per advise of @smdflea and replace with exact same part. PRD8607 should be restored with the correct value. Replacing the resistor with a high value wont fix it. You need to understand how Timer-ON logic works. I'm still hopeful for a fix as you have both the enable present on pin7-8.