hi
i have lenovo t61p laptop nvidia chipset i am facing problem about charging my laptop charge the bettry and but when i unplug the charger laptop shutdown ..... and not power up with charge bettry ..... any one hae a solution about this issue
Thanks

Measure and post voltages from all pins of Q10.

leg number 4 have 5v and 11 v on other legs

Measure voltage in drain of Q13 (VINT20) (with and without charger)

drain have 19v

And without battery?

Sorry I wanted to say without Charger.

with out bettry

drain have 10 to 11 v with out charger ......

It is very important to know the value of VINT20 without charger.

Without charger give 9v and after plug the charger its give 19v

It seems low voltage from battery. Bad battery?

How many volts is it rated? (check it in battery label)

battery is working on my working laptop thats problem in mainboard

Q10 has 11.7 volts in its drain, and is connected to the source of Q13.

If Q13 has 11.7 volts in its source, and 9 volts in its drain, (VINT20) then the internal diode are damaged, and mosfet Q13 seems not being saturated, so replace it whit a new one, or an equivalent.

i have changed but have same problem

Do you get same voltage measurements as before?

Something don't match.

i changed q13 q10 all have same condition

Battery must have 10.8V, I'm not sure only 9 volts will be enough.