You pcb does not have any fuses
Go back to basic
Link out tamper in panel,if clear fault on wiring or lid not on detector
You say it was ok until you did last detector,start there.shorts on cable not wired correctly?
Go back to basic
Link out tamper in panel,if clear fault on wiring or lid not on detector
You say it was ok until you did last detector,start there.shorts on cable not wired correctly?