I have HP G6 laptop with small problem i guess. its working nicely without an issue but when it turns off, it cannot power up (turn on) again. However if battery taken out ant put it back again its working. So i think there is something with the discharging circuit or somewhere else which is not fully discharged.
Anyone had this kind of trouble?

first of all desirable to test with another battery and update BIOS

There was some kind of a problem in PQ6 and PQ8. I guess they were not functioning properly. But when i checked them pinout readings were ok. however after i changed those components laptop get back to work as it was. Thanx for your kind support.

p.s. i replaced new RTC battery plus update to the latest bios after reassembled.

Everythings going well except without battery same problem emerged. With battery everythings look fine. But customer said that this is enough for now. So i gave it back.

Customer brought it back and asked me to give it a try and this time i replaced Super IO chip as well. Problem solved this time and I applied same solutions for few latest HP notebooks which were showing symptoms like sudden shut downs, only the 1st time laptops can be start. no power with blink codes. mainly there were in SIO and BIOS (EC+MAIN).