Before killing your original module, please make sure it can't be repaired.
If it is (sometimes) showing "0" or "1", then mostlikely the module can be repaired.
If it is showing strange random digits -no numbers- then it is most likely dead.
Any module that fits the watch can be a donor.
This P2 has a NSC module in it and works great.
( allthough the digits are a bit maller )