I have recently seen a few pictures of optical fibre connectors taken by a microscope after those connectors had been cleaned. The picture states, that the connector fails IEC 61300-3-35 norm. Like theese two bellow:
But the network with theese connectors is up and running without any problems and it was running ok even before cleaning the connectors. The installation is cca 10 years old. My question is: when is the right time to re-weld optical pigtails, are theese pictures really alarming or we can wait another year without any new pigtail's welding?