Chosen Solution
I have already been through this thread Stuck in continuous apple logo loop, turns off when cable removed? Unfortunately, my situation is compounded by the fact that my phone has no power left. Thats how it started in fact. So you plug in the phone and it shows the battery icon but only for about 5 seconds. Then it immediately tries to boot despite not having enough power. So it goes back to charging mode of around 5 seconds and repeats. It seems its trying to boot without enough power. So even if I try the above steps, it just goes back to battery icon mode for 5 seconds and never even tries to boot up. Any thoughts?
The problem was with the battery. I got it replaced. All good now.
it could have aproblem with the charging port. try checking the connections on it.