Asus X555LD Rev. 3.1 no power

[Conste]

Hey there,
I have a problem with a defective laptop I recently purchased.

Asus F555L, board X555LD Rev. 3.1.

The laptop is dead, no power on is possible, battery is not charging, no LEDs.

19v are there, also 5v and 3.3v, but only at some points, not on the bios chip. Main power generator is getting warm..so I think it could be short somewhere.

Can you give me any advice of how to fix it?

Thanks in advance.

Constantin

[jasko_jacker]

Re: Asus X555LD Rev. 3.1 no power

Check and report voltage on battery connector and check +3VA_EC

[Conste]

Re: Asus X555LD Rev. 3.1 no power

Hello,
+3VA_EC is at 0,06v - so nothing.
Battery is
0v
0v
0v
0,275v
0,06v
0,06v
2,6v
2,6v

All measured with reference to ground.

Thanks.

[caspian]

Re: Asus X555LD Rev. 3.1 no power

Now measure +3VAO on PSL8101.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

3,226v - I guess U8100 is the central power supply for 5 and 3,3 ?

[caspian]

Re: Asus X555LD Rev. 3.1 no power

that is right for PU8100.
Now measure voltage on both sides of PR9100 and PSL9101.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

PR9100 on both sides 3,2v

PSL9101 0,06v

[caspian]

Re: Asus X555LD Rev. 3.1 no power

thus it seems PU9100 needs to be replaced.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

okay, is there any way to Bridge the part?

I tried to Bridge it, took the 3,3v and put it to +3VA_EC, but no signs of life...but the power consumption Drops from 2,5W to 1W..

[caspian]

Re: Asus X555LD Rev. 3.1 no power

Diese bridging ist keine gute idee. If you want to bridge it, you have to think about lots of things first.
how much voltage on pin4 of PU9100 ?

[Conste]

Re: Asus X555LD Rev. 3.1 no power

PIN 4 should be 3,207v.

PIN4 goes to the power button according to boardview, am I Right?

Can u give me a recomendation for a hot air Station, just shouldn't be too expensive.
WIll be my first hot air action

[caspian]

Re: Asus X555LD Rev. 3.1 no power

If pin4 is 3v or more before pressing the power button, replace PU9100.
If you find an old model of QUICK rework stations in your city, it should be cheap but powerful. I use QUICK700. It worth finding a used one of QUICK700.

https://www.amazon.in/Quick-700-Rewo.../dp/B00P8RF7GW

[Conste]

Re: Asus X555LD Rev. 3.1 no power

okay, I will order some parts

What About a QUICK 857DW+? It is less than 100€ here in Germany

Or a quick 2008?

[caspian]

Re: Asus X555LD Rev. 3.1 no power

QUICK 857DW+ seems to have a max temperature of 100'C. it is too low.
quick 2008 seems to be digital. So I do not recommend it.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

both of them are digital, DW857+ is adjustable from 100 - 450°C, but has a Pretty low power consumption.

2008 has more power and can be adjusted from 100 - 500 °C, why don't u recommend it?

[Conste]

Re: Asus X555LD Rev. 3.1 no power

Hello again,
I ordered the Quick 2008. I will come back to the laptop when the parts arrive.

Thanks for the advices

[caspian]

Re: Asus X555LD Rev. 3.1 no power

it is possible that some other component is damaged in addition to PU9100. So, it is possible that you need to fix some other component after replacing PU9100. But it is also possible that only PU9100 be the problem and the laptop gets fixed after replacing PU9100.
For rework station, search this forum. there are some threads that recommend what rework stations to use.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

Yes, we will see.
Is it possible to desolder PU9100 and then put power on to board to measure the power consumption or to check if power supply is still getting hot? Or would this destroy something?

[caspian]

Re: Asus X555LD Rev. 3.1 no power

it is not required to do this test.

[Conste]

Re: Asus X555LD Rev. 3.1 no power

Hello,
I managed to desolder the part - the power IC doesn't get warm anymore, so there could really have been a short in PU9100.
I will report when I soldered the new IC inside.