Bnc cable with power messed up for cctv

[shocksl]

Hi I have stupidly cut the cable to push through the wall . Idea was to join them back together.

There's 2 wires inside blue and a white one. The white one has copper strands exterior around it.

When I joined it back together. The camera didn't work.

I'm unsure if it's down the cable I've knackered now from that bit. Or I might have nicked it from outside when trying to put on the cable clips when clipping against exterior wall.

So I guess what I'm asking is. Theoretically can I fix this cable from where I cut it. If so then I need to examine the wire from outside but I require ladders to do so.

You can see from the pics there is the 32 stranded copper that I need to attach. Which did before. That's very flakey some strands fall off

Thanks

 

[Avo Mk8]

There's 2 wires inside blue and a white one. The white one has copper strands exterior around it.

When I joined it back together. The camera didn't work.

Blue?
You haven't joined it completely back together! The copper screen around the wires needs to be continuous, ie you need to connect the two bits of braid together with a bit of wire.
I suspect the braid is used as a return path for powering the camera, so it won't work if that is not continuous.

For a "proper" repair, you should keep the length of unscreened wire to a minimum, or obtain some braid or copper foil to cover it, connected to the existing screen, but you will probably get away without that.