Question ASUS UX31A won't start. Black screen, no LEDs, buzzing sound coming from motherboard when AC adapter is plugged in.

Romanio0089

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Sep 22, 2019
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Hello, I need some help here.
My ASUS UX31A won't start anymore after a fan cleaning session. At first, after reassembly, there were the power LED, F2 LED, and Caps Lock LED all lighted up but with a black screen. Now, it became worse, black screen, no LEDs, and a strange buzzing sound coming from the motherboard when AC adapter is plugged in. AC adapter LED is green and sometimes, is orange but if I unplug it and plug it back, it becomes green again... I tried all troubleshooting I could find on internet.
Here's what I did yet :

· Electrical discharge - unplugged battery, pressed and hold power button for 1 minute, plugging AC adapter and test.
· Trying to boot without battery.
· Unplugging and plugging back all motherboards connectors.
· Checked from burnt or damaged parts on the motherboard. Nothing found there.
· Pressing and holding power button for 30 seconds.
· Remove SSD and tried to power on.
· Disconnected IO board and tried to power on.
· Verified keyboard and power button connector. Nothing is loose there. I reseated it just in case and still nothing.

Nothing worked there so I need help.

Maybe the power button has gone bad, so if you know what pins to short to power on the laptop, im interested. The buzzing sound I think comes from the chip marked JC EC 225. That's the marking ON the chip though and I couldn't find anything about it online. There is no other markings around the chip...

Here is a schematic if needed : schematic link here
Motherboard model : UX31A2 MAIN BOARD REV. 2.0

Thanks in advance for your time.
 
Last edited:
May 8, 2020
4
1
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0
Hello, I need some help here.
My ASUS UX31A won't start anymore after a fan cleaning session. At first, after reassembly, there were the power LED, F2 LED, and Caps Lock LED all lighted up but with a black screen. Now, it became worse, black screen, no LEDs, and a strange buzzing sound coming from the motherboard when AC adapter is plugged in. AC adapter LED is green and sometimes, is orange but if I unplug it and plug it back, it becomes green again... I tried all troubleshooting I could find on internet.
Here's what I did yet :

· Electrical discharge - unplugged battery, pressed and hold power button for 1 minute, plugging AC adapter and test.
· Trying to boot without battery.
· Unplugging and plugging back all motherboards connectors.
· Checked from burnt or damaged parts on the motherboard. Nothing found there.
· Pressing and holding power button for 30 seconds.
· Remove SSD and tried to power on.
· Disconnected IO board and tried to power on.
· Verified keyboard and power button connector. Nothing is loose there. I reseated it just in case and still nothing.

Nothing worked there so I need help.

Maybe the power button has gone bad, so if you know what pins to short to power on the laptop, im interested. The buzzing sound I think comes from the chip marked JC EC 225. That's the marking ON the chip though and I couldn't find anything about it online. There is no other markings around the chip...

Here is a schematic if needed : schematic link here
Motherboard model : UX31A2 MAIN BOARD REV. 2.0

Thanks in advance for your time.

Hi,
I have the exact same problem as you have. I ordered a new motherboard since my insurance company told that would be the error.
After replacing the motherboard with no Battery in, I still get the green-orange thing like you did. Now when adding the Battery it looks correct with the orange led in charger. But still nothing happens when turning on the laptop. I didn't test for keyboard/power on button but I guess it must be the only possible that can be faulty since I got a new Motherboard.

I might be able to help you. As I told when on battery after replacing the MB, I get the same error with charger just lightning green (I have 3 chargers to test with, so it cant be that part). I think if you have the same issue and tested the keyboard/power ON button, you should get a fix by replacing the battery.
At least my charger goes steady Orange now, so I guess the new MB works. I just don't know how to fix it. Might check the power on button but otherwise I'm lost for ideas.
 

Romanio0089

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Sep 22, 2019
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Hi,
I have the exact same problem as you have. I ordered a new motherboard since my insurance company told that would be the error.
After replacing the motherboard with no Battery in, I still get the green-orange thing like you did. Now when adding the Battery it looks correct with the orange led in charger. But still nothing happens when turning on the laptop. I didn't test for keyboard/power on button but I guess it must be the only possible that can be faulty since I got a new Motherboard.

I might be able to help you. As I told when on battery after replacing the MB, I get the same error with charger just lightning green (I have 3 chargers to test with, so it cant be that part). I think if you have the same issue and tested the keyboard/power ON button, you should get a fix by replacing the battery.
At least my charger goes steady Orange now, so I guess the new MB works. I just don't know how to fix it. Might check the power on button but otherwise I'm lost for ideas.
Thanks for that, I realize the battery might be the source of the problem. But after doing some more tests, it became worse, a lot worse. Now when I plug in AC adapter, nothing happens, no buzzing sound and AC LED is green. I unplug the charger, plug in the battery and the motherboard starts steaming. I then unplugged the battery and it stopped and I realized a small chip had some kind of outward dent and some burn marks around it. Unfourtunatly, I can't find anywhere to source the same chip to replace it and I don't have any junk motherboard with these small chips. So, I'll end up replacing the motherboard at some point, but I didn't even think of the battery so thanks ! For my side though, my keyboard and power on button is fine since when the motherboard was still making the buzzing sound, when I pressed on the power button, I heard the same buzzing sound as when I plug in AC. Another possibility for you, you maybe got a faulty motherboard or it broke while shipping so try sending it back and get another one. PLEASE take the a motherboard with the revision 4.1 as I think it solves some kind of issues with previous versions. The laptop I have was bought nearly after it was released so, I have the revision 2.0 and I realized some things changed with revision 4.1 and I know they are more reliable I think.
 
Last edited:
Reactions: Samsonite82
May 8, 2020
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Hi again,
It sounds like the battery caused the issues in your end. Did you test with no Batt in it at an earlier state and did you get the steady Green led in charger at that time?

I just checked which MB I just got. It is a rev 4.1 and I actually think it works, since the Led in the charger is now Solid orange when I assembly the unit completely. Strange, it was still lightning green when I didn't put on the backcover and battery. Maybe it's a safety thing, I don't know.
Is it tricky to test the Power button/keyboard for errors? I'm pretty sure thats where my fault is but I dunno how to fix it.

I ordered two MB's - one for UX31A and one for UX31E since I wanted to fix my two older, dead laptops. Payd 250 dollars in total, shipping included if you think about replacing your MB. Hopefully I manage to get just one of them to work again.
 
Reactions: Romanio0089

Romanio0089

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Sep 22, 2019
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I unfortunately can't help you that much for your power button issue because I already searched about it (when the board was not buzzing yet) and I found nearly nothing. The thing is, the battery shouldn't make my board die because it just worked completly fine before all of that happened. The other thing is, the laptop should boot up without the battery so yeah im a bit confused about all of this LED thingy at this point. I never had such an issue before, except when I was such an idiot and left the AC on a dead laptop with one chip that was getting SO MUCH hot and I was like, yeah it's fine, 10 minutes later (I actually forgot about it) the laptop was steaming and the DC jack section was burning ! I cleaned it up with some iso alcohol and I made a terrible desoldering job and I broke the board itself...

But anyways, here's a way you can try to power on the machine without the power button :

Try disassembling the keyboard and try to find the pins of the power button that goes to the cable that connects the keyboard and power button to the board. Then short the pins of the board itself that correspond to the ones on the cable of the keyboard and power button and it should turn on the machine, that is the only solution I found.
 
May 8, 2020
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Thanks for your help - I will try that tomorrow after spending most of the day disassembling and assembling my two faulty laptops to replace the Motherboards. The UX31E seems like not working at all - still just green led when attaching the power adapter.
From reading about Asus in general now on Trustpilot, I think my next laptop should be another brand - though these Zenbooks looks sweet. I just got a Zanbook s13 actually, which after 3 weeks has some problem at the power adapter/USB C that disconnects if you barely touch the cable.
So I guess our best option would be trying something new. Anyways - good day and thanks for the talk. /Sam
 

Romanio0089

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Sep 22, 2019
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I have finally bought a new motherboard. It's a REV 4.1 and fan is always spinning at full speed. Seller is telling me it's because the version is different, so I am trying to find a proper fan. At the end of the day, the battery wasn't the isse for me.
 
May 8, 2020
4
1
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Hi,
Good news if it actually starts. I managed to fix my UX31E with a new motherboard - or actually the problem was the AC-adapter so that was pretty lame. My UX31A still doesn't work though. I'm almost sure it's something to do with that freaking power button. You said you verified that connectors was as they should be from the keyboard. How would you be able to see that?
After replacing motherboard it seems like it does take power/AC-adapter goes to orange, not always steady though, but still. So my last hope is to test that power button if I could somehow.
 

Romanio0089

Prominent
Sep 22, 2019
16
1
565
0
Hi,
Good news if it actually starts. I managed to fix my UX31E with a new motherboard - or actually the problem was the AC-adapter so that was pretty lame. My UX31A still doesn't work though. I'm almost sure it's something to do with that freaking power button. You said you verified that connectors was as they should be from the keyboard. How would you be able to see that?
After replacing motherboard it seems like it does take power/AC-adapter goes to orange, not always steady though, but still. So my last hope is to test that power button if I could somehow.
I think your power button is dead. What I said to do was to try to find, by dissasembling the keyboard, the pins that correspond to the power button on the power button + keyboard connector on the motherboard. The power button is using the same connector with the keyboard, but it is seperated at at some point I think. After you found the seperation, you need to take a look at the cable, and there is some kind of visible lines on it. They correspond to a pin. When you found the correct ones, short them.

I made a post about my fan running at full speed here btw : https://forums.tomsguide.com/threads/asus-ux31a-fan-running-at-max-speed-after-replacing-motherboard.473233/
 
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