ASUS ux410u - No power no charge

[Spider1211]

Re: ASUS ux410u - No power no charge

Just to be sure: you believe top pad is ground because we have a huge track or is there any other reasoning?

In part, yes but not entirely. I also looked at surrounding components. If you look to the left of the capacitor, there is 2 solder pads. The bottom pad is going to another solder pad which connects to another solder pad whose layout is that of a SOT23-6 and therefore cannot be ground(also it is a thin trace). The top pad is shared with the top pad of the cap. Assuming the 2 pads next to the cap is where a component belongs, shared pads usually are for common grounds or power.

Just to be clear, this is just an assumption. Hence why the last resort is to use the pinout of the chip as reference to confirm for sure.

[Spider1211]

Re: ASUS ux410u - No power no charge

The chip close to the cap has "548 TI 711 ATCK". Didn't find the datasheet yet.

You could request help through another post with title "Help identify component". Put the reference as well as a clear picture showing the whole chip (and reference on board if available). Am sure someone will be able to identify it.

[Spider1211]

Re: ASUS ux410u - No power no charge

I was re-reading your initial post and.....

The good news is that I have another ux410u that is working perfectly, so, I could compare if needed.

need I say more

[alexvan59]

Re: ASUS ux410u - No power no charge

I was re-reading your initial post and.....

need I say more

Yes, it's actually my personal computer (initially, I bought the "dead" one to make sure I have all pieces in case something goes wrong with it). I wanted to avoid opening it. Will continue for now to try to do without it (because I want to learn ). If unsuccessfull, I will reopen my personal one .

[Spider1211]

Re: ASUS ux410u - No power no charge

I would suggest you open it just to verify which pad of the cap is ground so you can proceed with troubleshooting the short. Its to save time mostly really

[alexvan59]

Re: ASUS ux410u - No power no charge

I would suggest you open it just to verify which pad of the cap is ground so you can proceed with troubleshooting the short. Its to save time mostly really

Seems like another forum members has my boardview (I've seen you replied to him too). Maybe better to wait a little bit. Getting the boardview would really help me.

[alexvan59]

Re: ASUS ux410u - No power no charge

Ok, I have the boardview now and it seems mostly accurate.

The component I was trying to identify is PU8801 which is POWER SW. SN1409049DPUR TI QFN-14. The shorted cap is PC8816. It means I have +3VSUS shorted which goes to 62 points on the board.

So, I will do another round of voltage injection on this line. Will see.

@spider: thank you so much for your help today and the ebay seller thanks you too!

[Spider1211]

Re: ASUS ux410u - No power no charge

You are welcome! That's great, Report back when you have any update.

[Spider1211]

Re: ASUS ux410u - No power no charge

Are you comfortable with removing and resoldering PU8801? I had a look at the boardview and +3VSUS also goes to the CPU/PCH. I would try to first eliminate any potential faults before actually resorting to voltage injection.

PU8801 looks to be a TPS548, try removing it first and check if the short goes away. If no change, then consider injecting voltage.

[alexvan59]

Re: ASUS ux410u - No power no charge

Are you comfortable with removing and resoldering PU8801? I had a look at the boardview and +3VSUS also goes to the CPU/PCH. I would try to first eliminate any potential faults before actually resorting to voltage injection.

PU8801 looks to be a TPS548, try removing it first and check if the short goes away. If no change, then consider injecting voltage.

Will do that. Not have a lot of time today.

Actually, while looking at the board view, I realized that the highest probability were either pu8801 or a dead cpu (because most/all of the other elements on this line seems to be resistors that have a low failure rate). This line is totally shorted.

[alexvan59]

Re: ASUS ux410u - No power no charge

Hi,

Did voltage injection: really hard to feel any hot spot on this line. I had to go 2.2V and 1.6A.
There, I had a light feeling of hot on CPU. I've put some alcohol and the result is this one:https://youtu.be/j4vOIhsMhRM. It's not as clear as the EC but the alcohol is really "alive" and as soon as I inject voltage, I see it moving differently.

I tried to put alcohol on caps that are under this area to assert the CPU is not hot only because a component behind is hot. No effect.

So, my conclusion is: CPU is dead. So, dead EC, dead CPU and two bad pins: that's the official announcement that I have a donor board now and many other components (screen, battery, usb extension, keyboard, housing).

I would like to try the screen and the battery. Is there a way for me to test them without putting my "working" mainboard in the computer?

Thanks,

[velektronic@gmail.com]

Re: ASUS ux410u - No power no charge

Hi

Please how type in Asus UX410U mainboard is this chip as in attached picture ?

On my MB is burned and not see sign.

[Stevedb]

Re: ASUS ux410u - No power no charge

Photo is not clear enough you can use some cool paste or toothpaste to see what is written on the chip.

[SMDFlea]

Re: ASUS ux410u - No power no charge

Hi

Please how type in Asus UX410U mainboard is this chip as in attached picture ?

On my MB is burned and not see sign.

Its a ROHM BD82034FVJ-GE2 .Datasheet https://cdn.badcaps-static.com/pdfs/...9fb9560043.pdf

Use this boardview https://www.badcaps.net/forum/showpo...28&postcount=7

[mon2]

Re: ASUS ux410u - No power no charge

@SMDFlea

[kostukas1985]

Re: ASUS ux410u - No power no charge

548 TI 711 is TPS548 on aliexpress https://www.aliexpress.com/item/4000199632451.html