Asus VivoBook F510UA-AH51 won't run on battery after motherboard replacement

[dhenion]

I'm working on my sister's laptop: Asus VivoBook F510UA-AH51 - The motherboard died so I replaced it.

The original board was:
ASUS X510UNR REV 3.0 A

The replacement board is:
ASUS X510UNR REV 3.0 B (identical except B vs A - I couldn't find an A board anywhere. Visually they are identical.)

It boots right up on the replaced motherboard and everything works fine on the new motherboard - but it won't run off battery. When I disconnect the charger it immediately dies. When I plug it back in and reboot the system - it still shows the battery at 100%. I don't think the battery is just immediately discharging - but it seems the computer just won't switch over to it.

Windows shows the battery is good, and powercfg /batteryreport also shows the battery is good (less capacity than when it was new, but good - see attached image)

I reset BIOS to defaults and BIOS is already at the most recent version I could find (v310)

I removed the battery related items in device manager - rebooted, they got re-installed - no effect.

I double checked all the connections to the motherboard, all look good.

I held the power button down for 1min multiple times - no effect.

I have verified the charger and port are good - I get a good 19v on the motherboard from the charging port.

I swapped in a test hard drive and did a clean windows 10 install - same situation - battery seems good but won't run from it.


I can't figure what else to do. I ordered a battery just to try, but I don't think that's the issue.

Think this is just a faulty AC/battery switchover circuit on the replacement motherboard? Or is there something stupid I'm missing???
Some odd difference between the "A" version of the motherboard and the "B" version? I couldn't find any docs on that.


Thanks for any help.

[mcplslg123]

What is the voltage on pin4 of dc-in mosfet?

[dhenion]

If you can help me to find where that is on the mb I can measure, thanks.

[SMDFlea]

If you can help me to find where that is on the mb I can measure, thanks.

You can find it using the boardview -> https://www.badcaps.net/forum/troubl...manual-x510unr . Use BoardViewer software to open the boardview file -> http://boardviewer.net/ .Alternatively you can use Openboardview which you might find easier to use,but you will have to add the fz license key (available somewhere on the forum) before you can view fz files.
https://github.com/OpenBoardView/OpenBoardView/releases

[dhenion]

To update this thread - I put in a new battery and all works fine now.
I suspect it was one of three things:
A) The old battery died just by coincidence when replacing the motherboard
B) I somehow damaged the battery while replacing the motherboard
C) There was some sort of incompatibility between the old battery and the new REV 3.0 B motherboard.

My money is on C. A is highly unlikely and while B is possible - I was being very careful.
It was just odd that everything showed good with the old battery, it just wouldn't switch over to it.
Anyway - case closed