Fault finding procedures can be taught but experience can’t be!
So, when something was working until you looked at it or did something that caused a change on your telecom system, the first part of fault finding should always be to ask yourself, ‘what did I do last?’
This of course can be extended to what was done last by someone else. When troubleshooting a system where there are complex interactions, this simple question may need to be supported by making copious notes as procedures are performed.
I realise this is all obvious but we are often blinded by what we have done ourselves and may fall foul of the ‘I know I did it right’ syndrome. I know this because I have wasted a lot of time checking and rechecking something because I assumed I had set it up right in the first place. That was only the firing order on a car engine.
What if it had been something really difficult?