Chosen Solution
Battery was replaced, and found out lighting connector was worn out, intermittent charging/connection, changed lighting connector but battery is not charging also noticed battery does get very warm on discharge, currently at <20% charge. Device will boot up on connection when plugged in.
You have ruled out parts so it would point to one of the charging IC’s on the logic board either Tristar or Tigris. This repair would require a repair shop that offers microsoldering.
