Acer Aspire E1-531 Not powering ON with AC adapter.

[shijeesh]

Dear Technical Team,
Acer Aspire E1-531 Not powering ON with AC adapter, but it powering ON with Battery . The 19v is only in PQ9 Drain and 0v in PQ9 Source and 0.4v in Gate terminal. Charging IC BQ24725ARGRR.

[ktmmotocross]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

this ic is sooooo faulty that i bet your is bad. have 5 laptop in a row with that bad chip.

if wanna run system without it/no battery charging, no battery/, just inject 19V to base of first mosfet, or to 4th pin of this ic /ACDRV/

ofcourse as first check if u have acdet and acok signals that detects adapter

[shijeesh]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

BQ24725 pin 5 ACOK = 0v and pin 6 ACDET=2.5v . Sometime its working PQ9 Gate voltage is 25.4v that time battery charging is ok

[shijeesh]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

Sir please reply

[ktmmotocross]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

my only reply is to change it. im allready waiting for new pieces if this ic.
i just inject 19v to acdrv signal, working without battery and waiting for new chips

[shijeesh]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

I need expert help for solve it.

[Ikung]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

try replace pq9

[Shadow255]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

I have exactly the same problem as shijeesh:
ACOK = 0v
ACDET=2.5v
VCC (on bq24725A) = 19V
ACDRV pulses (1Hz, 4V peak, 2.5ms width)

When pulsed, one can see the voltage at Vin being carried through to P1 (after PQ9) and also to P2 (after PQ10).

I do not understand why ACOK does not reflect the presence of power. The datasheet for bq24725A state the following requirement for ACOK to go high:
AC adapter detection open drain output. It is pulled HIGH to external pull-up supply rail by external pull-up resistor when voltage on ACDET pin is between 2.4V and 3.15V, and voltage on VCC is above UVLO and voltage on VCC pin is 275mV above voltage on SRN pin, indicating a valid adapter is present to start charge. If any one of the above conditions can not meet, it is pulled LOW to GND by internal MOSFET. Connect a 10kΩ pull up resistor from ACOK to the pull-up supply rail

Any ideas?

[shijeesh]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

Replace PQ9 and PQ10

[rievax_60]

Re: Acer Aspire E1-531 Not powering ON with AC adapter.

Also,
A common protection method used in most laptop designs is a diode between the ACDET pin and the Vbatt rail. A resistor bleeds a small current to the Vbatt rail which normally causes the voltage to rise. If there is a short or leakage to ground, the voltage doesn't rise enough causing the diode to keep the ACDET pin too low.