I recently attempted this repair but with a new battery installed the device now won’t power on. The old battery was severely swollen and despite being as careful as possible I tore the outer foil wrapper and even tore the connector on the battery during removal (the battery did not smoke or seem that it had shorted). Regardless, it’s pretty clear that the device is shorted and is now bricked, right? Is there any remedy or is the motherboard “fried”?

I wish I would have seen the comments on step 18 about putting an insulator (paper) between the old battery and motherboard when removing. This may have saved my device.