Just replaced the FCAM ass.
Success!! Everything is back to normal.
I'm not sure why exactly exchanging batteries made the FCAM ass. fail in two identical situations, I can only assume it was because OP and I didn't think to remove front screen entirely and it was damaged in the process.
Best thing is, I contacted the battery seller as they advertised a better battery than what I received and they are sending me another one. For the Au$16 mistake of requiring another FCAM ass. it looks like this phones going to last for years to come.
Best of luck OP, please keep us updated.
Cheers.