I've tried all of the above given tips. Cleaned the battery contacts, looked for the battery contact soldering damage on the board seems fine. I even went to the extent of changing the battery with another, but could obly find another used original battery but they both seem fine as ive looked at the amperage and a constantly 3.8-9 mostly.
But my problem persists, which is the random restarts and or random blank screen, where you gef a blank screen for almost 5-10 minutes before it restarts.
And yes it happens even with the battery on! I guess I'll try the usb connector