XIAO nRF52840 New units no longer power up from battery pins?

i think one more the bottom of a good one…

My personal XAIO NRF-LoRa sandwitch in a medical product bottle… Not the best solder job… but solid and made with flux and pre-tinned pads and not a thermal controlled iron and very bad tip… but the new tips are not compatable with my favorite radio shack iron set… what da?