I looked into the motherboard and one pin from a cable was not attached to the motherboard (see pic) i tried to solder it but not good (first try), also im waiting for the flux to arrive.
Q&A:
1.Which logic board: NM-A831 indeed!
2. Charger IC (BQ series) @ PU101: yes it is BQ series

Do i need an oscillosscope to test where the voltage travels? or there is another way before i solder the power cable to the motherboard?

Hi! so my E570 screen backligth went off a couple months ago and now i wanted to repair it. While i was looking for the problem, i saw that there is a fuse missing (see red arrow in attached photo) on the display circuit board. Moreover, the fuse F1 (blue arrow) is cooked since I tested it with the multimeter and it is not beeping. I bought the used laptop a few years ago and there is marks that some repairs were made on him. Then, when I wanted to check the voltage, i discovered that i have a battery problem (i pressume). How do i know that? when i plug the charger to the laptop, there is an...