BQ24193 low VBUS input in a nsw oled

[xiran64]

Hi to all!

I´ve a NSW oled, that won´t charge.

I´ve remove the fuse, to see if is the charging port, and put 5v to the nearby capacitor in Vbus line, it have a very low consumption, 0.11A.

I´ve have a nsw lite, to compare, an it don´t have consumption, without the battery both, only board. I´ve replace mt and bq, with same result...

Pin one of bq, it´s onle 0.18v

Can somebody guide me please?

 

[thesjaakspoiler]

There is a ton of information in the Switch section of this site :
https://www.retrosix.wiki/first-stage-boot-short-checks

 

[xiran64]

Thx for answer thesjaakspoiler!

I´ve see that page, but i´ll check again.

UPDATE:
I´ve check the MAX77620 & MAX77812, and have this voltages:





UPDATE2:
Voltages in BQ24193:

 

[jkyoho]

missing 1.3v from MAX77620H is likely tend to be EMMC or CPU related, unless you are powering the board from external DC supply not from battery

 

[xiran64]

missing 1.3v from MAX77620H is likely tend to be EMMC or CPU related, unless you are powering the board from external DC supply not from battery

Thx for answer jkyoho, i´am injecting voltage from an external power source, 4.2V to the coil

 

[jkyoho]

Thx for answer jkyoho, i´am injecting voltage from an external power source

show your setup

 

[xiran64]

show your setup

Here you have it, 4.2V@1A

 

[jkyoho]

Do you put 10k resistor next to battery connector?

 

[xiran64]

Do you put 10k resistor next to battery connector?

it's right

 

[jkyoho]

what's the current draw?

 

[xiran64]

what's the current draw?

According to the tutorial of retrosix, 1A

 

[jkyoho]

According to the tutorial of retrosix, 1A

No, I mean how much the board draws when you trigger power on

 

[xiran64]

No, I mean how much the board draws when you trigger power on

Ok, first try, with 4.2@1A, consumption of 0.188A, stables ( stuck between 100 and 300mA).
Uploaded to 2A:
1st try: Consumption variable, and voltage in battery pin, of 4.2V.
2nd try: Stable consumption of 0.188A
3nd try: same as 2nd

 

[jkyoho]

take a picture on emmc, any attempt sign?

 

[xiran64]

take a picture on emmc, any attempt sign?

Here you have it, Voltage included in surrounding capacitors, one is 0v

Post automatically merged: Nov 13, 2024

Checking the mosffet at the begin, near usb c, i´ve found a short in the first mosffet, so, i´ve exchange it, from another nsw lite, and the suspicious mosffet, works in the lite...

Short removed, and same... I´ll exchange one ics, with the nsw lite

 

[xiran64]

Ok, I replaced the m92t36, and now it charges the battery.

Maybe, that short in the mosfet, burn the second m92t36.

We are going to wait for the battery voltage to rise, because before, if I charged the battery separately, it would turn on, but it would not charge. made false charge

UPDATE:
These are the current voltages

UPDATE2:
No video =(, i´ll check

UPDATE3:
Ok, now, it works fine, no video was be, for a bent pin.

My conclusion is:
The nsw oled works, but do false charge, replacing the related ic charge, but it burns, by a mosfet in short.

Thx to all for your help!!!