Chosen Solution
Board was taken out of the phone Rear metal shield removed carefully using a temp of 220c Solid flux applied to NAND chip NAND heated to melt the flux, Left to cool Flux cleaned away with filtered water and a plastic toothbrush, lightly dabbed/wiped with a dry cloth, scrubbed again with dry plastic toothbrush Heated to 100c with hot air gun for 15 minutes to dry Then reassembled (with the metal shield left off). When connecting to Wifi through settings the spinning symbol shows but no connections. The home button has also stopped working. What went wrong?
I’m curious as to what problem you were trying to address by simply melting some flux on the NAND. The first thing that comes to mind is insuring that the interconnect cable, on the back of the logic board, was re-installed or not damaged. Whenever you apply heat to a logic board, even low heat, you always run the risk of collateral damage. If you “take you time” what you are really doing is applying more heat. Eventually, parts can become dislodged, get bridged with adjacent parts or simply blown away. You also have to consider that sometimes the damage happens on the reverse side, where gravity encourages components to “fall” off the board. There’s not really enough information to give a precise diagnostic but I would do a thorough visual inspection, preferably with magnification and then focus on the two subsystems and their related circuitry to see if anything is obviously wrong. After that, you need to start probing the circuits.
Try reinstalling the metal plate. It’s surprising what one little can do every now and then.
