Asus R556L - The laptop does not start on battery

[Glica01]

Asus R556L does not turn on on the battery. When the power is connected, it starts without any problems. The battery is good, holds 6 hours and charges properly.
It is possible to run on the battery itself but I must hold the Power button for 15 seconds and press Power again. Otherwise it won't start.
The motherboard is X555LD Rev.3.3.
Is there anyone who can help me find a problem? - maybe someone has a battery scheme for this board.
Please help!!

[caspian]

Re: Asus R556L - The laptop does not start on battery

you should measure voltages on the mainboard when the laptop does not turn on. testing another battery can help you a lot.

[jasko_jacker]

Re: Asus R556L - The laptop does not start on battery

I had a similar problem on an asus. If it turns on by press the button for a few seconds and then it works well, then the battery properly powers the motherboard. It could be a problem related to the ec or its firmware.
If you don't have another battery , install battery battery mon from passmark to detect the battery status.

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Approx. battery after mounting to the board has successively on the first two pins 8, and on the next two 3.27V. The power button is 3.27V on one side, but when I press the start button, there is nothing at the output. And yet the button itself should be good because the power supply starts well. I wonder if the battery should not go 5V on the power button.
The power transistor seems to be good. Measured by meter. I want to add that the laptop is flooded, but well drained. After all, everything works well.
I don't have a schematic and I don't know what voltage should be on the EC.

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Approx. battery after mounting to the board has successively on the first two pins 8, and on the next two 3.27V. The power button is 3.27V on one side, but when I press the start button, there is nothing at the output. And yet the button itself should be good because the power supply starts well. I wonder if the battery should not go 5V on the power button.
The power transistor seems to be good. Measured by meter. I want to add that the laptop is flooded, but well drained. After all, everything works well.
I don't have a schematic and I don't know what voltage should be on the EC.
Battery mon is nothing battery mon indicates that the battery is good. Maybe someone has a board power supply scheme, because I don't know what the voltage should be on the button when the battery is installed. 3.3 or 7.6V. currently there is 3.3V on the button. Is it enough for the laptop to start?

[caspian]

Re: Asus R556L - The laptop does not start on battery

3.3V for the power button is good.
X555LD has a repair guide and boardview. you can use them instead of schematics:

https://www.badcaps.net/forum/attach...3&d=1566828845
https://www.badcaps.net/forum/attach...8&d=1501852385
https://www.badcaps.net/forum/showthread.php?t=60549

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Thank you but I can't create these FZ files.
I tried OpenBoardViewer and Fritzing. Or I can't.
I measured the voltages according to this diagram - X555LD_RG.pdf and it seems that the inverters have the correct voltage and are not short-circuited. What else should you check?

[caspian]

Re: Asus R556L - The laptop does not start on battery

focus on the sections of the mainboard which are related to the battery. measure voltages on those sections when the laptop cannot turn on.

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Okay. I measured the keys on battery power and found the culprit, I think. It's M1830. One of them does not conduct voltage. Can it be desoldered with a regular 40W butt?
Unfortunately I don't have hot air and I have to buy. Or hot tweezers. What do you think?
I would put a photo of the damaged item in the forum, but I don't know how.

[Glica01]

Re: Asus R556L - The laptop does not start on battery

https://www.badcaps.net/forum/attach...1&d=1578334922

[caspian]

Re: Asus R556L - The laptop does not start on battery

To desolder that IC, you need a hot air station. you can watch YouTube videos to learn desoldering.
However, input voltage at Pin 4 on the left IC is 0 v. that is why it does not pass its input.
what did happen to the left IC? it is not clear in the photo. is it dirt or burn mark on the IC?

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Yeah. I ordered a hot air soldering station. As for the left IC, it is probably damaged (burned out) because the laptop was flooded.
Fortunately, after washing and drying everything works except starting from the battery. I will have a soldering station on Monday or Tuesday. Since there is a problem with the purchase of IC, I also ordered damaged asus for parts. If I mention this burnt system, I will let you know. Under the microscope, it looks like it's the same as standing next to it. For now, thank you for your help.

[Conste]

Re: Asus R556L - The laptop does not start on battery

You could try to bridge the MOSFET first. If it works then, it will probably also work with new MOSFET (if MOSFET gets power).

[piernov]

Re: Asus R556L - The laptop does not start on battery

No. Don't bridge MOSFETs randomly. If it's bad, replace it, if it's good, don't touch it.

[Glica01]

Re: Asus R556L - The laptop does not start on battery

Okay, but I can't find boardviev for the X555LD rev.3.3 - maybe someone has?

[piernov]

Re: Asus R556L - The laptop does not start on battery

https://www.badcaps.net/forum/showpo...67&postcount=3