Detecting which component failed in laptop power circuit

[Korime]

Laptop powers up from the battery but it does not from the charger and it doesn't charge the battery either.

I have measured voltages on power circuit components (see in the attached image).

http://postimg.org/image/wnd643gnb/

Or for better resolution, download pdf schematic file (page 6).
https://www.scribd.com/doc/273197386/Toshiba-Satellite-C650-655-Motherboard-Inventec-Schematic

In "blue" are voltages measured when only charger is attached. In "green" are voltages measured when only battery is attached. In "italic" are voltages that prevail when both charger and battery are attached.

"6-7V" means that multi-meter is reading unstable voltage which goes from around 6 to around 7 volts up and down. Does this indicate malfunction and of "Q6003"?

If not, which component/s are not working properly and need replacing?

Update: I have replaced Q6003 and everything stayed the same, so it's not that component.

[CaptainObvious]

Maybe I skipped over it while I was reading, but I didn't see where you've tested the laptop charger? (unless this is what you mean by circuit components)

More often than not the charger will die before your charging circuit, 7/10 times I get a laptop that won't charge in my shop it's due to a faulty laptop charger. (2.99/10 would be for the DC Jack replacements, don't think I've come across a faulty charge circuit yet)