Asus UX31E rev 3.2

[pimoz]

Hello!

Well, my baby old ultrabook died. I was changing the thermal paste and after puting it back together it wont work anymore.
The ultrabook is Asus UX31E board revision 3.2.
If I plug in the AC it turns on by itself. Fan spins, power led is on but nothing on the screen. Same with external VGA and HDMI. If I try to force shut it down (5s power key) it just turns on again.
If I unplug AC and have it run only on battery it stays off. I can get power led and fan working by pressing power button. No screen however.
I tried looking at power flow. I get all rails except VGFX_CORE which has 0V.
PL8003 coil measured good. I'm guessing the problem is RT8166. Or could it be the mosfets driving VGFX_CORE?
Otherwise the board looks ok and nothing is overheating or smoking.

In attachment you'll find schematic diagram and fz file.

Please help, I'm really not able to buy a new computer right now (corona and economic situation)

[Stevedb]

Re: Asus UX31E rev 3.2

Try first an hard bios reset. Remove the bios battery short the bios battery for 5 sec. Then place everything back. If this doesn't work . Make a picture in harddefenition from voltage on every coil. Then remove power. Then resistance value from every coil to ground.

Good luck

Best regards

Steve

[pimoz]

Re: Asus UX31E rev 3.2

What do you mean short the bios battery? Do you mean short the battery itself or the pins on the motherboard to which the battery is connected? What good would shorting the battery do?

Here are the resistance and voltage values from coils:
PL8800 146.7 kohm (jumps around untill going still); voltage goes from 10V to 16V then back down
PL8100 9.16 kohm; 3.369 V
PL8301 0.466 kohm; 1.508
PL8101 5.56 kohm; 5.07 V
PL8400 388.6 ohm; 1.806
PL8200 35.6 ohm; 1.066 V
PL8003 17.5 ohm; 2 mV
PL8700 70.4 ohm; 0 V
PL8005 20.5 ohm; 0 V

When measuring resistance ac, battery pack and bios battery were plugged off.

Thank you for looking into this

[stingerchamp]

Re: Asus UX31E rev 3.2

You have power sequence available at page 4 of schematic

Check pm_rsmrst# signal

Check all signals from 1 to 18

[pimoz]

Re: Asus UX31E rev 3.2

All signals from 1 to 18:
3VA_EC 3.298V
EC_RST# 3.268V
VSUS_ON 3.295V
ME_SusPwrDnAck 3.357V
SUS_PWRGD 3.290V
PM_RSMRST# 3.273V
ME_AC_PRESENT 3.294V
PWR_SW# 3.291V
PM_PWRBTN# 3.294V
ME_PM_SLP_M# can't find it
PM_SUSC# 3.356V
ME_PM_SLP_LAN# can't find it, maybe SLP_LAN# 3.357
PM_SUSB# 3.355V
ME_SLP_M_EC# can't find it
SUSC_EC# 3.284V
SUSB_EC# 3.284V
ME_+VM_PWRGD can't find it
ME_PWROK can't find it
SYSTEM_PWRGD 3.326V

Where I wrote I can't find it, it means i can't find it in FZ file (maybe some other name?)

[stingerchamp]

Re: Asus UX31E rev 3.2

Every signal is generated hmm

Have you checked flashing of bios

Do you have 3v at bios chip, when you press power button what is voltage on power button when you press it, does it go down to 0

Have you tried hard reset as suggested above?

Remove rtc cell from motherboard while in cold state without adapter and without main battery and other device such as WiFi card SSD drive etc.

Press power button 30sec and release

Put back rtc cell after 30min

Shorting means in cold state with twizer or wire
Connect rtc cell section positive terminal to ground or negative terminal for few seconds but make sure no power attached

[pimoz]

Re: Asus UX31E rev 3.2

Yes, 3V at bios is present.
Yes, power button pulls down to 0V.
Hard reset was done, no change.
I removed everything except fan and laptop screen.

I will look into reprogramming bios.

The weird thing is that motherboard powers up when plugged into ac by itself. And even if I try to force shutdown holding power key for 5s, when i release it powers up again.

Any other ideas? VGFX_CORE is still the only power rail not comming up.

[stingerchamp]

Re: Asus UX31E rev 3.2

Flash good bios

Rsmrst# voltage must be 3v

Did you check ram section?

If ram section ok then we check for gfx

[pimoz]

Re: Asus UX31E rev 3.2

Ok I will reflash good bios.

How do i check ram section?

[stingerchamp]

Re: Asus UX31E rev 3.2

I have created a thread for it for DDR 3, DDR 3 L, DDR 4

https://www.badcaps.net/forum/showthread.php?t=91082

[pimoz]

Re: Asus UX31E rev 3.2

My baby is saved!

I've connected the bios chip to raspberry pi via spi and reflashed it. It now works

For reference i'm attaching bios file. https://www.badcaps.net/forum/showthread.php?t=91316


Thank you very, very much Wish you a merry christmas and a happy new year

.

[stingerchamp]

Re: Asus UX31E rev 3.2

Congratulations

[Stevedb]

Re: Asus UX31E rev 3.2

Good job !!!

[apppostol]

Re: Asus UX31E rev 3.2

Guys, hello everyone! The situation happened exactly as described! Just after rebuilding the laptop, the symptoms became like the author's. I flashed bios from the forum thread and it all worked. Thanks for the info!

Парни, всем привет! Случилась ситуация точно как описано! Просто после пересбора ноутбука, симптомы стали как у автора. Прошил bios из ветки форума и все заработало. Спасибо за информацию!