Like anything else:
Isolate the Problem.
Apply a steady signal to free your hands. A CD player or something. REmember, we are looking for loss of signal, not tone, so it doesn't matter if the signal itself sounds good. Now gently pull out and repush each patch cord to see if one is involved. Might be the cord or the jacks, but if we know WHERE we are mostly there. In fact, just grasping the middle of each patch cord and wiggling it in a circle reveals much.
The fact you can fiddle with it and it works screams that it is a connection somewhere. So if the connections don't get it, grab a screwdriver by the blade, and whack the body of each pedal sharply. This is a mini version of my fist-whacking the chassis of an amp. If any pedal reacts, it is suspect.
Gently grasp each control on each pedal, one at a time, and slightly tweak its setting. Does moving ANY control bring the sound back?
If you are using a supply rather than batteries, then each and every power connection needs to be wiggled and stressed. Don't forget the other end of the power wires.
lets say you have ten pedals.
[airplane mode]"you have ten pedals"[/airplane mode]
then plug your signal into the input of #5 instead of #1. Still lost or now works? And the other way. Plug the amp cord into the output of #5 instead of the last pedal output. This could tell us which half of the pedal lineup has the problem.