iPhone 6 suddenly died and now will not power unless plugged in

Hey guys

so I’ve read a fair bit about this issue but mine seems to be something other than what I’ve read.

so long story short. I was using the phone, all was well until it suddenly died.. at 63% battery! So I did what most would do and plugged it in to the genuine apple charger with its genuine apple lead. Phone came on.. no charging icon just straight to the apple logo, but not any further sort of in a boot loop.. so after a bit of reading I came to the conclusion duff battery and ordered a new oem one, fitted this.. still no power!

when plugged in it will power to the logo, and then proceed to boot loop, can’t get any power out of the battery whatsoever.. will only show signs of life when plugged in but will not boot into iOS..

theres 3 years worth of photos of my kids on this phone, so need to get it sorted even if it’s just to get the photos off of it..

any ideas what to try next?