Amilo LA1703 no power

[rookieme]

I need your help guys once more.
At the attached schematic I found out that I haven't got any voltage at the drain of Q24 [AO4407] which is driven by U16 [BQ24721].
The gate of Q24 is driven high [18,5 V].
Should I try a replacement of U16 or something else could be the fault?

[ridamouh159]

Re: Amilo LA1703 no power

try to change BQ 24721

[atsio]

Re: Amilo LA1703 no power

try to change BQ 24721

Why?

[dj_ricoh]

Re: Amilo LA1703 no power

Post the voltage from the charging IC bq.
Then we will see if it req. Changing.

[atsio]

Re: Amilo LA1703 no power

I need your help guys once more.
At the attached schematic I found out that I haven't got any voltage at the drain of Q24 [AO4407] which is driven by U16 [BQ24721].
The gate of Q24 is driven high [18,5 V].
Should I try a replacement of U16 or something else could be the fault?

Q24 is a p-channel fet. Voltage at gate should be around 12,5v. 18,5v means that BQ does not find any dc adapter.

[rookieme]

Re: Amilo LA1703 no power

So i'm confused what to look for.


<Post the voltage from the charging IC bq> - could you be more specific?

[dj_ricoh]

Re: Amilo LA1703 no power

Yes . Very simple but hard to do.

Voltage on every pin from bq24721.

When you write down the voltge you write the name of the pin to

Like this
Pin 1-Acin 3.3v
Pin2 - acok 2.4v this is a ex.

[rookieme]

Re: Amilo LA1703 no power

My meter might not be very accurate

pin1 CHGEN 0V
pin2 ACDRV 18.5 V
pin3 ACN 18.5 V
pin4 18.5 V
pin5 ACDET 1.1 V
pin6 BYPASS 10.2 V
pin7 EAO 0 V
pin8 EAI 0 V
pin9 FBO 0.14 V
pin10 AGND 0 V
pin11 VREF5 0.03 V
pin12 VCC 18.5 V
pin13 SDA 0.05 V
pin14 SCL 0.04 V
pin15 TS 0 V
pin16 ISYNSET 0 V
pin17 IOUT 0 V
pin18 BAT 0 V
pin19 SRN 0 V
pin20 SRP 0 V
pin21 SYNN 0 V
pin22 SYNP 0 V
pin23 SYS 0.01 V
pin24 BATDRV 0.05 V
pin25 ALARM 0.05 V
pin26 PGND 0 V
pin27 LODRV 0.26 V
pin28 REGN 0.13 V
pin29 PH 0 V
pin30 HIDRV 0 V
pin31 BTST 0 V
pin32 PVCC 18.5 V

[dj_ricoh]

Re: Amilo LA1703 no power

Vref5 0v?

Wow

Eder you got a short and stops this ic to power up or this ic its DUD

[ridamouh159]

Re: Amilo LA1703 no power

[ridamouh159]

Re: Amilo LA1703 no power

You must found
CHGEN 3.39V

AND

Sda 3,39V
Scl 3,39 V
COMING From ene

YOU MUST VERIFING IF THERE 3.39V AROUND- AUTOUR DE ITE IT8512E

[ridamouh159]

Re: Amilo LA1703 no power

pardon my english is bad- no good

[Blacktek]

Re: Amilo LA1703 no power

Q24 is a p-channel fet. Voltage at gate should be around 12,5v. 18,5v means that BQ does not find any dc adapter.

so if BQ cant detect adapter, whats next? should he be looking at R285 and all the Caps on the same line?

[megaraider]

Re: Amilo LA1703 no power

imo bq24721 is NOT detecting the adapter! "1.2V rising-edge" vs 1.1V measured.
In this situation the REGN pin voltage should be at 4.6V.
BUT since your battery is dead you can not tell if the bq24721 is burned or if it is in over voltage.
(most likely it's in over voltage since BYPASS pin is raised)

[rookieme]

Re: Amilo LA1703 no power

Well I received the ic and replaced it.
VREF now has the 5 V and board came back to life!
Thank you all.

[megaraider]

Re: Amilo LA1703 no power

Great news