Asus X555L backlight shuts off when on battery

[Dannyx]

Good day folks. Very strange issue I've got with an Asus lappy here. I haven't heard or seen something similar before so it's very difficult to track down.

Here goes: when I got it, the battery was bulged on the inside of it. It was pushing against the touchpad, so that's the initial issue the owner reported, as they had no idea the battery was causing the back-pressure. I took it apart, removed the blown battery and left it without one since it runs just fine on the AC adapter alone. Meanwhile, the chaps said they'd like a new battery put it after I told them it's blown, so fair enough, they pay me, I order it up and after a long wait the battery turns up.

I install it and try powering up the thing. It does come on, but now there's no backlight...as soon as I plug the AC adapter in, the backlight instantly comes on...can't remember if the bulged battery did this. I can't recall if it had any bit of life left in it and turned on at all.

Something's very wrong inside, so now I'm kinda stuck with a fairly expensive battery and a laptop I can't charge money for.....the schematic isn't very helpful because like most laptops, the PCB isn't marked, so I have no idea where to look first or what's causing the issue...I get 19v on pin 1 of the LVDS cable when plugged in and the backlight is on, which indeed goes away when I pull out the cord and it fluctuates 1-3v...the laptop keeps on going just fine, but the backlight doesn't switch over. The only schematic I found is this one, though I'm not sure it's for the proper board, since it's not mentioned anywhere. Just in case someone has a brainy idea or has encountered this before....again, very difficult. I can provide pictures if need be. Cheers and thanks.

[Th3_uN1Qu3]

I think i have a boardview for that. I'll check it a bit later and get back to you.

[Dannyx]

Thanks mate.

[mielta]

Hi
See if its help

[Dannyx]

Ugggh dumb question: how do you open those ? Haven't used board views before. Thanks.

[vinceroger69]

Originally Posted by Dannyx

Ugggh dumb question: how do you open those ? Haven't used board views before. Thanks.

This is what i use
https://openboardview.org/

[Dannyx]

Thanks for the input so far, but it looks like this is going to be a mental exercise trying to figure out what went wrong rather than a hands-on approach trying to fix the thing, because I already closed the laptop and am underway to returning the battery which the seller luckily agreed to take back. Let's see...

[Dannyx]

The software won't install I'm afraid....just says has stopped working when I try running the installer...

[vinceroger69]

This is the same software i use on windows 10 laptop its also what louis rossmann uses on his you tube videos so should work fine i will remove and re install it on this laptop and give it a try

Edit yes works fine using windows 10

[Dannyx]

I'm on win7 and I managed to find an alternative simply called boardviewer...I can open those files and located the connector for the panel and whatnot, but I must admit I'm not sure how such a boardviewer works. From what I understand, when I click on a pin, it highlights all other pins connected to it. In this case, I'm looking at the pins 38-40 of J4502, just so we're on the same page and they seem to be connected to AC BAT SYS. Upon clicking on the pins it shows me what else goes to those pins as well. Strange how it dies when you pull out the plug...

[setiyo]

Originally Posted by Dannyx

Ugggh dumb question: how do you open those ? Haven't used board views before. Thanks.

try this program bro

[Dannyx]

Can you please reupload the schematic ? I grabbed it at work and worked perfectly, but now it's telling me the archive is damaged...

[petehall347]

could it be a software problem ? power settings gone wrong somehow

[Dannyx]

I doubt it, because AC_BAT_SYS 19v, present on pins 38-40 of the LVDS connector I mentioned, disappears when the AC adapter is pulled out. That seems to be the only "power" going into the display connector. It's not a control signal that cuts out - it's the supply itself that seems to die. Strange how nothing else dies...

[vinceroger69]

Originally Posted by Dannyx

Can you please reupload the schematic ? I grabbed it at work and worked perfectly, but now it's telling me the archive is damaged...

hopefully this will work

[Dannyx]

Yes it does. Thanks

[shuky]

hello
i have same problem did you fix it ?
have you got the board schematics ???

thank you

[SMDFlea]

Originally Posted by shuky

hello
i have same problem did you fix it ?
have you got the board schematics ???

thank you

There is only a repair guide, and the boardview is already posted .

[shuky]

thank you . but its only sample diagram

[SMDFlea]

Originally Posted by shuky

thank you . but its only sample diagram

There is no schematic, just the Repair Guide with test points. The boardview is already posted.