lenovo g570 not working on battery

[abbas_govani]

hi guys
i am getting trouble in solving this lenovo g570.
board model PIWG2 LA-675AP.
Working fine on adaptor and charging battery. But when i remove charger laptop power off. i already changed battery. but problem remains same.

and also checked PU401 which is TPS51125. BUT NO SUCCESS.
please help.

Thanks in advance.

[smali]

Re: lenovo g570 not working on battery

Check the PQ303 (FET) and find the schematic.

[smali]

Re: lenovo g570 not working on battery

As you said pu401 (TPS51125) which is not concern with charging or battery adopter conversion it is 5V and 3V regulator. the charging IC is PU301 (ISL6251).

[abbas_govani]

Re: lenovo g570 not working on battery

pq303 is working ok. i will check isl pu301.

[smali]

Re: lenovo g570 not working on battery

OK have you received battery voltage on PQ303 drain without adopter if yes then shunt the drain and source of the PQ303 without adopter for temporary checking what the result?

[abbas_govani]

Re: lenovo g570 not working on battery

checked there is 11v on pq303,
i had also replaced isl6251.
but same working on adaptor not on battery

[abbas_govani]

Re: lenovo g570 not working on battery

the laptop is charging but cuts off power when pull out adaptor. i had cross check battery battery is fine.
i am getting 11v on every 18 v rail on battery (adaptor not attached)

[smali]

Re: lenovo g570 not working on battery

oh ok it mean you have received battery voltage on rail line. i think the voltage with low ampare . check the voltage on PR302 with multimeter with battery connected only and press power Btn if the voltage is drop from 11v that mean that amp low.and also check the 3vlp on tps51125 with battery only?

[smali]

Re: lenovo g570 not working on battery

and also check ENTRIP1 and ENTRIP2 section.

[abbas_govani]

Re: lenovo g570 not working on battery

there is no power on pwr btn on battery without adaptor. with adaptor all volts ok.

[abbas_govani]

Re: lenovo g570 not working on battery

on pr302 there is 11v.

[smali]

Re: lenovo g570 not working on battery

ok i think you have problem in entrip section . remove pq405 (small dual FET) near the tps51125 and then check voltage on power switch on battery only if receiving then entrip section problem.

[smali]

Re: lenovo g570 not working on battery

sorry before removing bq 405 first pq407 ( transistor) collector short with ground and check voltage on pwr btn and post on both satuation result.

[abbas_govani]

Re: lenovo g570 not working on battery

there is no power on collector while on battery.
but on adaptor there is 4.2 adaptor attached.

one more this i am having same board so i am going to replace the pq405 and pq407 and will post the result

[abbas_govani]

Re: lenovo g570 not working on battery

changed both fet pq405 and 407 but no success.

[abbas_govani]

Re: lenovo g570 not working on battery

oh ok it mean you have received battery voltage on rail line. i think the voltage with low ampare . check the voltage on PR302 with multimeter with battery connected only and press power Btn if the voltage is drop from 11v that mean that amp low.and also check the 3vlp on tps51125 with battery only?

no change in volage on pr 302.

had checked pin 8 3vlp reading is 3.351 v

[meritosari]

Re: lenovo g570 not working on battery

-voltage PD101,PQ101?

[smali]

Re: lenovo g570 not working on battery

do not replace as i said in above post first short the collector pq407 ( center pin) with ground and check voltage on power switch if no change then remove pq405 and check if voltage receiving on switch then you have problem with PD101 and pq 101 where you have not receiving the VS voltage from pq101 or pd 101.

[smali]

Re: lenovo g570 not working on battery

and also check Pu101 (LM393)