Asus Zenbook UX330UA odd power issue

[ElJap0]

The power button does not turn the machine on. But when the adapter is plugged in, it will boot properly (without pusshing the power button). When in the OS, the power button responds. Can anyone shed some light on this or provide a schematic or boardview?

[peste]

Re: Asus Zenbook UX330UA odd power issue

change the bios for the beginning

[ktmmotocross]

Re: Asus Zenbook UX330UA odd power issue

The power button does not turn the machine on. But when the adapter is plugged in, it will boot properly (without pusshing the power button). When in the OS, the power button responds. Can anyone shed some light on this or provide a schematic or boardview?

check voltage of bios battery if u have it

[ElJap0]

Re: Asus Zenbook UX330UA odd power issue

I don't see a cmos, and there are a few IC's that look like they can be the BIOS. Should I just hit pin 1 on anything that looks like a BIOS chip? Also, there is no CMOS on the IO board

[SMDFlea]

Re: Asus Zenbook UX330UA odd power issue

On boards with no CMOS battery the board will power the RTC from the main laptop battery.What condition is your battery in,have you tried another battery

[ElJap0]

Re: Asus Zenbook UX330UA odd power issue

Battery is fine. It holds a charge and charges properly when I boot into an OS. But the weird thing is that it boots automatically when the chrager is plugged in (similar to a MB Mobo externally with an 85w adapter), and once in the OS the power button functions. But if you leave the adapter out (with a fully charged battery) and try to turn it on with the power button, it does nothing

[Retro-Hipster]

Re: Asus Zenbook UX330UA odd power issue

A question on the battery ElJap0.. When you say it is fine, how have you determined this? Have you taken a multimeter and tested the voltage of the pack? If so, have you tried testing it under load?

There are many reason why a laptop battery can show that it has charged/is charged when it is still damaged. This could also point to a charge controller issue. If you are comfortable opening up the unit and taking the battery out, maybe stick a little 20-watt 12v bulb on across the leads of your multimeter with some crock clips and then probe the battery to see what the voltage reads. That would give a 1.7a test load and should give you an idea of what the batteries voltage is under load. (Something this maybe.)

It is always important to understand that batteries can read the correct voltage when they have no load, but dip down below operating voltage when under load. Since this is a Lithium battery it is going to have a mosfet/under voltage protection.

[ElJap0]

Re: Asus Zenbook UX330UA odd power issue

Could you clarify how this would help to troubleshoot (no sarcasm intended). The power button not triggering the P.O.S.T. with a charged battery would lead me to think something is wrong with an S5 rail. That maybe the keyboard (or something else) is not being supplied power. Your input is appreciated, but could you clarify your thoughts on why a bad battery would be the culprit (again, no sarcasm intended)

[Retro-Hipster]

Re: Asus Zenbook UX330UA odd power issue

Oh, no problem. This was me going off of what SMD flea was mentioning about laptops that do not have CMOS batteries. The idea behind this would be that the battery that is showing as fully charged main fact just be reaching its Target voltage quickly due to damage but then quickly dropping below its cutoff voltage. At that point the mosfets would not be providing any power to the laptop and you would not be getting any power. I guess the real take away from what I was saying was just that people often test batteries just by checking the voltage without a load only to find later that the battery cuts off immediately when a load is applied.

[ElJap0]

Re: Asus Zenbook UX330UA odd power issue

How do I test a laptop battery? And could the battery still be the culprit if the laptop stays on without the adapter, after being powered on by connecting it (without hitting the power button)?

[ElJap0]

Re: Asus Zenbook UX330UA odd power issue

Also, you're saying it might be a mosfet that is looking for a signal from the battery before letting the signal from the power button come through (or something of the sort (a "p" or "n" mosfet that relies on the battery signal))?

[Weelcup]

Re: Asus Zenbook UX330UA odd power issue

Also, you're saying it might be a mosfet that is looking for a signal from the battery before letting the signal from the power button come through (or something of the sort (a "p" or "n" mosfet that relies on the battery signal))?

Hi.
I had a quick look on this post. Can you check the voltages of the battery pins while it is connected to the board. To see they provide any voltage to the board. Cuz I would suspect the battery to begin with.

[Troos]

Re: Asus Zenbook UX330UA odd power issue

I'm having the same exact odd power symptoms. Was there any resolution to the issue? I checked and my battery seems ok - it is fully charged (12V) and maintains that voltage when plugged into the mother board. I'm checking to see if there is an updated BIOS to download.