ESP8266 Community Forum

schufti wrote:optically it looks ok, but you may have removed / broken one of the copper interconnects between the top/bottom layer on the pcb. Look at the removed pins for any minute "copper tubes" sitting on them.

I think this may be it. There is indeed some visible copper on the backside of the module, and I've found that when I press around on the board in this area, it is sometimes recognised (I was even able to upload a sketch). But it is very unreliable. Is there some way to salvage the board or have I killed it?

either use your multimeter in "peep-mode" (continuity check) and test top/bottom side of pin or try to figure out where the left over copper has been located originally. Worst case ist you have to check 4 pin locations per leftover. Then just solder (top & bottom) a short lenght of cut-off wire (resistor etc) into it.