acer aspire V3 771G VA70

[zhang]

Re: acer aspire V3 771G VA70

Please check pin 48 for sio chip
me_ac_present
and resolder sp2219 if it is available to be soldered

[poweron]

Re: acer aspire V3 771G VA70

Please check pin 48 for sio chip
me_ac_present
and resolder sp2219 if it is available to be soldered

thank you very much ... only that now it happened to me to make a short with the tip of the tester between pin 11 and 12 of U8100a that it burns a lot, I have to restore the situation, surely I have to replace the qfn then you update, thanks

[poweron]

Re: acer aspire V3 771G VA70

what can I put in place of the TPS51225 (U8100A)?

[SMDFlea]

Re: acer aspire V3 771G VA70

what can I put in place of the TPS51225 (U8100A)?

TPS51225C = APW8822C

https://www.badcaps.net/forum/showthread.php?p=829615

[poweron]

Re: acer aspire V3 771G VA70

thank you, since I have several main laptops, is there a way to know on which projects a certain integrated is mounted?

[poweron]

Re: acer aspire V3 771G VA70

[QUOTE=poweron;904006]these are the voltages on U8800 BQ24725:

voltage value column: first adapter only - second adapter + battery - third battery only

pin 1 = 19v 18,8v 11,3v
pin 2 = 19v 18,8v 11,3v
pin 3 = 19v 19,3v 0,38v
pin 4 = 25v 19,3v 0,38v
pin 5 = 3.2v 3,2v 0v
pin 6 = 2.6v 2,6v 0v
pin 7 = 0v 0v 0v
pin 8 = 3.2v 3,2v 3,2v
pin 9 = 3.2v 3,2v 3,2v
pin 10 = 3.0v 3,1v 3,1v
pin 11 = 3.2v 11,2v 17,3v
pin 12 = 3.2v 11,3v 11,3v
pin 13 = 3.2v 11,3v 11,3v
pin 14 = gnd gnd gnd
pin 15 = 0v 0v 0v
pin 16 = 5.9v 6v 0v
pin 17 = 5.9v 11v 11v
pin 18 = 3.2v 11,3v 11,3v
pin 19 = 3.2v 11,3v 11,3v
pin 20 = 19v 19v 11,2v

after replacing the U8100 it also turns on with only the adapter and with only the battery, if after inserting the battery the adapter is connected this goes in protection, if instead I insert the battery after connecting the adapter this does not go into protection but does not charge the battery even if the amber LED is on, if at this stage you press on button it turns on but it is the battery that powers it, the problem can be U8800?

[zhang]

Re: acer aspire V3 771G VA70

how much is the power consumption on bench power supply
without turning on
adapter + battery
and compare it with adapter only
( without turning on )

[mcplslg123]

Re: acer aspire V3 771G VA70

check discharge fet, it might be shorted. Your adapter is going in protection mode when battery is connected means battery voltage is reaching on ac voltage points.

[poweron]

Re: acer aspire V3 771G VA70

the problem is caused by Q8800 which is shorted between S and D, after its replacement everything works properly, even the battery is charged regularly, I thank everyone for the precious collaboration

[frica]

Re: acer aspire V3 771G VA70

+1

[frica]

Re: acer aspire V3 771G VA70

Exellent reparation!! I am newbie in electronic repair and I enjoey much when I read a success reparation. But I am a question:

The voltage in shorted transistor Q8800 was measured in the message #7. The owner of the laptop measured 19v in Source and in Drain. The short was not discovered in view of these measures. why? Are these values not enough to reveal the shorted situation??.

But in a shorted MOSFET what is the typical values of voltage for Drain, Source and Gate?? In this laptop the Gate voltage for Q800 would be also 19 volts?? It is an indicative of short that the voltage in the 3 pins have the same values??

Thanks!