Asus X551CA no power and no led

[DS-1]

Hi,

a friend of mine gave me this laptop (it has soldered cpu and RAM).

No led, no power with a working ac adapter. I've tried to remove the battery, but nothing happens.

Has anyone experiences with this laptop?

[DS-1]

Re: Asus X551CA no power and no led

No one can help me?

I believe it's hard to find schematics and info about this laptop!

[meritosari]

Re: Asus X551CA no power and no led

No one can help me?

I believe it's hard to find schematics and info about this laptop!

Photo as reference?
Let picture speak

link scan notebook High quality
https://docs.google.com/spreadsheet/...=sharing#gid=1

[DS-1]

Re: Asus X551CA no power and no led

The board is the same one you can see in photo. If you need specific pics, just ask.

Photo as reference?
Let picture speak

link scan notebook High quality
https://docs.google.com/spreadsheet/...=sharing#gid=1

[alihomee]

Re: Asus X551CA no power and no led

how the main volts .....battery connector......3v 5v.......

[dj_ricoh]

Re: Asus X551CA no power and no led

check the dc jack
they are notorius for breaking

[meritosari]

Re: Asus X551CA no power and no led

No one can help me?

I believe it's hard to find schematics and info about this laptop!

I've got the boardview and share it for this forum

[pcnetch]

Re: Asus X551CA no power and no led

Check power button voltage. if present and after pressing going 0v try re-ball pch.

[DS-1]

Re: Asus X551CA no power and no led

I have 19v on dc jack mainboard solder points, so it's not broken.

I have 3v on 2 battery connector pins.

I'll check power button voltage, as @pcnetch wrote.

[DS-1]

Re: Asus X551CA no power and no led

It seems I can't open .fz schematic file with no app (Fritzing says it has the first line corrupted, TSICT seems to work only with .BOM files, PCBRepairTool doesn't show the file, when I put it in FAB folder).

[meritosari]

Re: Asus X551CA no power and no led

Use pcbrepair tool, when open first time you've got error license, open again pcbrepair tool, then use ctrl+f11, direct to folder you have it. Its done.

[DS-1]

Re: Asus X551CA no power and no led

@meritosari, thanks a lot.

I've checked voltages again. I have no volts on power button and I have 2.80v circa on the last two pins of the battery charger socket.

I've noticed that when I plug the ac adapter on, something in the area of the picture I've attached become very hot.

[meritosari]

Re: Asus X551CA no power and no led

where? they have name. LOL
PQ, PU,PC or PR, please mentioned

try touch with finger..I think you've find the culprit.. maybe that component was shorted/broken

[DS-1]

Re: Asus X551CA no power and no led

ehhh...I know I was too generic, but it's not that easy to understand with fingers which one of those small components is hot!

That's why I posted the area: maybe is it a common fault in that area?

I'll try to find a way to understand which one is shorted!

where? they have name. LOL
PQ, PU,PC or PR, please mentioned

try touch with finger..I think you've find the culprit.. maybe that component was shorted/broken

[meritosari]

Re: Asus X551CA no power and no led

measure resistance to gnd on some point below without adapter/battery plug in
1.pjp8100 (19v rail short or not)
2.pjp8102 (3.3v short or not)
3.pjp8101 (5v short or not)

measure resistance mosfet near area that was hot if shorted (Drain-Source, S-D)
use magnifying glass to look if small component (caps) was burn

[pcnetch]

Re: Asus X551CA no power and no led

If no Power button voltage, definitely System main power fail. I fixed two x551ca laps in last week. But not this problem. Try search IC number in google will give you IC's datasheet.Then check LDO Voltages.

[pcnetch]

Re: Asus X551CA no power and no led

If heating PCB in normal mode, definitely must be a short. specially cap etc. Do you have DC bench power supply. If you have can check short places easily.

[Blacktek]

Re: Asus X551CA no power and no led

i have the exact same board with a power issue, plugged in no power whatsoever. first thing i checked was the mosfets near the powerjack, one of them looks suspicious but for the life of me i cannot find the schematic for this board..im like 80% sure that whats causing the issue..why? because it has continuity on all pins(shorted).

Seems like the only place that might have the schematic is ***********? can any of you guys get it for me?

[meritosari]

Re: Asus X551CA no power and no led

The best tool for working with asus are the boardview+scan photo, schematic doesn't help cause the board without marking as other vendor.
I don't have access to vinafix, but if you scrool below on link @ktmmotocross the admin say no schematics, just boardview

Sorry for bad english

[Th3_uN1Qu3]

Re: Asus X551CA no power and no led

I have had a number of these lately. The issues ranged from bad MOSFETs in the DC in to shorted capacitors and the last one had the KBC shorted.

Be very careful about probing the power button connector or turning it on with tweezers - there is a 19v line right next to pin 1 (3.3v). You don't want to touch those two points together by any chance.