Acer A315-22 no power on

[pippo_one]

Re: Acer A315-22 no power on

Hi, over the weekend I took the liberty of measuring all the voltages of the Pu101 as suggested by @Prustel.. hoping that the values I post can be of help in understanding a possible solution.
I state that the measurements are performed with "pr107 and Pq107" unsoldered from the mainb and without battery (obviously discharged):
pin1=1,3mV
pin2=1,3mV
pin3=20nV
pin4=22mV
pin5=11mV
pin6=2,75V
pin7=2mV
pin8=8mV
pin9=80mV
pin10=0V
pin11=10mV
pin12=10mV
pin13=0v
pin14=free
pin15=18mV
pin16=11mV
pin17=160mV
pin18=40mV
pin19=160mV
pin20=160mV
pin21=8MV
pin22=0V
pin23=0V
pin24=6,1V
pin25=5,75V
pin26=0.80V
pin27=6,0V
pin28=19,6V
I also went to download the bq24781RUYR datasheet
and finding the bq247800RUYR
that reading around a bit it seems that they are the same
I hope with your help to find a solution

[Sephir0th]

Re: Acer A315-22 no power on

Regarding your previous measurements the Main power rail is partial shorted to GND with around 300 Ohms which was clarified in post #5 already. You were asked for a resistance measurement to GND of PR107 in post #2 already too btw.
However, actually this is the highest partial short I ever came across, so i am not sure what is going on here and I'd like if you can double-check this measurement with a second multimeter.

Also solder everything back what you have removed before since the issue likely isn't related to the DC-IN circuit. With one exception, leave PR107 out for the moment and measure resistance to GND of both pads to determine whether the low reading persists on DC-IN or load side.

[Techtiger]

Re: Acer A315-22 no power on

Since you have removed CLR
check the resistance in Diode mode bothe side of the line pin 1 & 2
Conforme ACN 330 Ohm ? ACP 305 Ohm ? PQ105 470 Ohm?
resistance in Diode mode CMSRC ACDRV ?
resistance in Diode mode PQ103 ?
Upload a close pic of the sector’

[pippo_one]

Re: Acer A315-22 no power on

1.....pin1-2 = 0.0029
2....I can't confirm they are wrong .seee point 1
3.....CMSRC ACDRV = 359 Kohm
4.....0,5556 ohm

the pcb tracks are all intact from the pu101 up to the pq103-105

measurements performed with pr107 and pq107 unsoldered from the pcb

[Techtiger]

Re: Acer A315-22 no power on

PR119 is it on MB or have you taken it off ? If not in MB put the black prode to GND point and Red probe to pin 1 side then take resistance in Diode mode same way for pin 2 because the second picture do you have posted seems to be the probes are in pin 1-2

[Techtiger]

Re: Acer A315-22 no power on

PR119 is it on MB or have you taken it off ? If not in MB put the black prode to GND point and Red probe to pin 1 side then take resistance in Diode mode same way for pin 2 because the second picture do you have posted seems to be the probes are in pin 1-2

For N channel MOSFET in future test this way

[pippo_one]

Re: Acer A315-22 no power on

Hi....I removed Pr119 from mainb, in diode mode I measured at pin 1=2.4637
pin2= no measurement detected,...

with the photo sent I re-measured pq103 and pq105 and they respect the indications you have shown me
only measure detectable black tip on "D" and the red one on "S" 0.55 ohm

Thank you

[pippo_one]

Re: Acer A315-22 no power on

any suggestions ?