Question laptop fan constantly runs when unplugged

[q4p395p31;q]

Asus ZenBook Flip UX560UQ Windows 10 64-bit BIOS Version 307

When I shut down the laptop the cooling fan runs at full RPM until the battery is dead.
If I connect the power cord (to outlet and laptop) the fan stops.
If I break power supply (by wall or laptop port) the fan starts.
Also, when laptop is off and power is disconnected the power button does not turn it on; the lights flash like its trying to start up and the fan stops for a second. I can only turn the laptop on when its power cord is connected.
The same condition occurs in hibernate mode, including the malfunctioning power button.
It does not occur in sleep mode. And the sleep button does not invoke sleep mode.
The power port seems sturdy (not too loose)

I have tried various BIOS settings (disable wake on lid open, disable some other things I don't really understand), but no settings seem directly related to power.
I have toggled Fast Start Up in the windows power settings; which did not help.

I seems like there is some kind of short or disconnect between the power button, the power port, and the battery. What allows electricity to flow from the battery to the fan, but also gets dissabled when the power cord is sending juice to the laptop? Has anybody heard of this before. What's your vote. Hardware issue or software issue? I'm leaning on hardware issue, but I don't know which component to replace first.

 

[mrmike16]

First of all, you shouldn't play with the BIOS without knowing what you're doing.
These issues are all related to the motherboard. First you can try resetting it (By taking out both the battery and the CMOS coin battery for 5-10 minutes before putting it back in).

The newest version of the BIOS of your laptop model I see from ASUS's website is 301, not 307. How was it updated?

 

[q4p395p31;q]

Thank you for your reply. Bios version 307 is from the ASUS website too; it's for model UX560UQK. I had V301 on it before the problem started; updating to V307 did not seem to change anything. I updated it using the "ASUS EZ Flash 3 Utility" built into all versions. I can flash back to V301, 202, or 303; EZ flash will take them all but none of that changes anything. I have disconnected the battery, pulled out and cleaned the fan, but did not see a CMOS battery. Do all laptops have them (ASUS FAQ was not much help)? I guess I'll have to take it apart further and hunt more. Any other thoughts? Thanks again.

 

[mrmike16]

Thank you for your reply. Bios version 307 is from the ASUS website too; it's for model UX560UQK. I had V301 on it before the problem started; updating to V307 did not seem to change anything. I updated it using the "ASUS EZ Flash 3 Utility" built into all versions. I can flash back to V301, 202, or 303; EZ flash will take them all but none of that changes anything. I have disconnected the battery, pulled out and cleaned the fan, but did not see a CMOS battery. Do all laptops have them (ASUS FAQ was not much help)? I guess I'll have to take it apart further and hunt more. Any other thoughts? Thanks again.

I have seen in some models where ASUS put the CMOS battery on the bottom (meaning the flipped side) of the motherboard. It is a pain to get to, if that is the case.

 

[q4p395p31;q]

It's actually right next to HDD. It's been a while since I took a PC apart. Pulling it didn't change anything. But since I had it apart I noticed the hard drive runs along with the fan. So if its plugged in (power cord connected) the laptop shuts down and boots up as expected. Without power cord, the laptop appears to shutdown but the fan and HDD stop for one second then start running on high speed. This all happens when I leave out the CMOS battery, too. Also, I checked it with my multi meter and its still kicking out 1.3v. It's so weird, why would the HDD also start up just because I unplug a laptop that's been shutdown through windows?

 

[mrmike16]

That is weird. Maybe try using another battery if anyone you know has one of these laptops as well. I'm leaning towards it being a hardware issue as well, as it isn't related to Windows. And the battery is what the laptop switches to when you unplug it, so that would be my first guess.

 

[scourge102]

I have an Asus Q504U that is doing the same thing: The fan runs when not plugged in. It will not restart if not plugged in, but does wake from sleeping. If I shut it down, it seems like the HDD is still running and when the battery gets low the fan just will not stop until completely dead.

My HDD motor stopped working and had to be replaced. Nothing had changed with the fan. I haven't tried taking the CMOS and regular batteries out yet.

I'm hoping this information will help find an answer. This problem is really annoying.

 

[mrmike16]

I think only ASUS can fix this with a BIOS update. Check that there aren't any newer BIOS versions available.