TUF505DT : No charge

[kurtspirit]

Re: TUF505DT : No charge

I just check again and it about 168kohm ~

[mon2]

Re: TUF505DT : No charge

This is an Asus? So no schematics are available?

This part is not the correct value.

Can you post a clear pic of this part?

Then we can seek out a replacement.

[mon2]

Re: TUF505DT : No charge

Asus will have followed the recommendations by TI for the charger IC.

Respectively, see attached. Very likely that the original current sense resistor was of the same value @ 10mOhms = 10 milli-ohms.

This resistor is now defective based on the measurements posted earlier.

If possible, take measurements of body size of this part and then we can try to hunt down a replacement.

[kurtspirit]

Re: TUF505DT : No charge

Hello,

Here is a picture from the zone. The two red marks are points where i find the measurement. If i follow the datasheet, ACN and ACP are 1 and 2 on the BQ.

https://ibb.co/8BfmRFy

And here is a picture from the zone. To be honest, i don't find the resistor. I don't find a boardview file for this board... Thank you really much for your help

https://ibb.co/Rc9DHhv

And i just find something on the other side of the board : I found a completely cut track on the other side of the map. I can fix it but I'm not sure if it's relevant. If a component caused this break, I wouldn't want to pry with a wire and cause a big, widespread short.
What do you think ?
Edit : after test, the two tracks are in permanent contact. Is this normal? I don't know but could this be one of the reasons for the problem?
https://ibb.co/GvZ66vF

[mon2]

Re: TUF505DT : No charge

The trace under the label you show does appear to be cut. Use a meter in the lowest scale and measure from the very top of the trace with the exposed copper to the start of the trace near the label.

Then measure the resistance again between acn and ACP pins. It should be a very low resistance.

The reading should be ~0 ohms. Confirm it.

If it is not, use a piece of wire to bridge the broken trace.

Then power up again and post the voltage to ground of ACN and then ACP.

[kurtspirit]

Re: TUF505DT : No charge

The problem is that the two traces side by side are in contact... I'm not sure that's normal
https://ibb.co/4YPkwmF

[mon2]

Re: TUF505DT : No charge

Hello.

1) post the pics only on this forum. Otherwise the links expire and this thread will be of no value.

2) yes the traces will appear shorted because of the low resistance current sense resistor.

3) focus only on the right side trace. Meter at start and meter at end of the right track. What is the resistance? You have exposed copper test points. The pic shows the trace to be broken. It must be fixed. Also the hole in the middle of this same right trace..is that hole broken? If yes then someone else is not connected due to the broken hole. This hole is called a PCB via. This via is used to take the connection from this side to the opposite side of the PCB.

[kurtspirit]

Re: TUF505DT : No charge

The trace is clearly cut. I'll put a wire instead.
For the pics, i'm sorry but when i use the link from forum , pictures doesn't appear in the message...

[kurtspirit]

Re: TUF505DT : No charge

Ok mon2, now the resistance is about 0.01ohm. Maybe i have to test with battery ?

[mon2]

Re: TUF505DT : No charge

Good. Now test again.

[kurtspirit]

Re: TUF505DT : No charge

How to thank you?!
The PC is finally charging! I'm so grateful, I never thought I'd get there. It's awesome ! I'm really happy and thank you ten thousand times

[mon2]

Re: TUF505DT : No charge

Well done. Kudos to @Piernov for spotting the large voltage drop. I saw it as well but did not think at the time, the drop was that large of a delta. It is great that you located the cut trace. That is true teamwork!!

[mon2]

Re: TUF505DT : No charge

How to thank you?!

Donate to the forum. Trying to convince the webmaster to host on Amazon servers to prevent downtime.

[Sephir0th]

Re: TUF505DT : No charge

Very interesting. Just to have a idea what happened here lately. For me it turned out, it was "just" a cutted ACN or ACP rail, no? So luckily, the voltage drop was measured at the charging controller itself instead of at the CSR. Otherwise we were still clueless...?

[kurtspirit]

Re: TUF505DT : No charge

To be honest, I don't know.
I think a Mosfet (I changed them all) caused this broken line but that's really a guess...
The previous battery had suddenly stopped charging for no reason, that's when something happened but it will remain a mystery.
I changed in the end: battery, the 3 Mosfets, the charging IC, a diode.
Thank you very much to everyone anyway, it's a pure pleasure to see the PC working again!