Can anyone help with an Asus board?

[gcain]

I'm not very familiar with PCs and need some help.

Asus X555LD.

Connect power, board turns on. Turn it off with the power button, and it won't turn on again until you disconnect the power for a few seconds. If the battery is connected, it has to be disconnected too before it wil power back on.

Originally had a blown backlight.
I can supply a boardview.

 

[Paul Daniels]

I've had a few of these to fix, not faults like yours though, however, check the board that holds the power button on the underside of the top deck for corrosion as a first step. Beyond that, I'm not going to be much use here.

 

[gcain]

Thanks Paul, appreciate the input.

The power button for this board is on the MLB itself. This behaviour is present when bench testing with no peripherals attached and the board has no visible corrosion.

 

[Paul Daniels]

Okay, my mistake there ( used to most of the X555's having the remote daughterboard and a 120mm long 5way FPC, though I know the X555 prefix is used on a lot of their range ). Good luck then, not overly sure what to suggest.

Badcaps might be of reasonable help, especially if you can get a hold of people like piernov (or on Rossmann's discord )

 

[gcain]

Thanks again Paul, handy having someone in my timezone.

I've reached out on BadCaps for help, will report back when I get it solved.

 

[aprendiz]

Voltages present when don't want to power on again ???

 

[dukefawks]

Blown backlight when swapping LCD and without removing battery. I bet the KBC is dead. ITE IT85xxE or something like that.

 

[gcain]

haha.
No one is admitting anything Duke, but I assumed that's exactly what happened.

Crazy how many shops swap LCDs without disconnecting the battery.

Will check on voltages when I get to the office.

 

[Inwerp]

Blown backlight when swapping LCD and without removing battery. I bet the KBC is dead. ITE IT85xxE or something like that.

isnt KBC supposed to form a voltage for power button?

call me stupid, i suggest gcain to reflash the KBC and BIOS as a first measure.
there are plenty of boards which behave like a dead ones just because of bios corruption.

 

[gcain]

well, I do have a clean bios binary hand, so flashing it would be easy... I'll do that just to rule it out.

 

[gcain]

dukefawks the keyboard still works okay. Is it fair to assume the KBC is okay?

I'll check the power rail on the power switch shortly.

 

[dukefawks]

No that does not prove anything!

 

[gcain]

Just getting back to this repair now;

Where do you suggest I go with it?

The power switch has 3.3v and goes low when pressed. If I put power onto the LID_SW the board boots up. Could it be thinking the lid is always closed?

 

[gcain]

I just powered it on before and noticed the IT8585E chip you mentioned gets blistering hot.
Another ASUS board here I compared with, it stays cold on.
Guess that's the first thingy to swap out.


Is there firmware on them?

 

[dukefawks]

What is the chip ITxxxx?

oh 8585

Yeah that does have internal flash. Need to program with SVOD or similar programmer.

 

[gcain]

I swapped out the IT8585 for another and all is well.

Thanks for helping with this one everyone.