DS-2CD2347G2-LU POE issue (Resistance too high)

[fevis]

I have 4x DS-2CD2347G2-LU connected to a DS-7608NI-I2/8P. After the initial setup (4 weekes ago), they all worked fine, but a few days ago, one of them stopped working.
When i check the NVR, the LEDS for this particular cam is not flashing like the rest. When i check POE status on the NVR, i see it says "Resistance too high". See screenshot. What does that mean?
After some time, it changes to "Connected" with around 3W usage, like the rest. But the LEDS are still turned off.
Before the cam stopped working, i had enabled the white flash, when it detected motion. This still comes on, when i move infront of the camera. But no image and i cant connect to the cam.

At the moment it is connected with a CAT6 cable (about 50m). I have tested connecting the cam with a short cable (1m) into the NVR and then the camera works.
Anyone have a suggestion what the problem might be?

 

[alastairstevenson]

At the moment it is connected with a CAT6 cable (about 50m). I have tested connecting the cam with a short cable (1m) into the NVR and then the camera works.

That may point the finger at the cable as being faulty.

Have you done a visual inspection of the cable ends?
How easy would it be to test one of the other cameras on the cable?
Can you use / borrow a cable tester to verify continuity?
Can you re-terminate ends to see if that eliminates the problem?

 

[fevis]

Have you done a visual inspection of the cable ends?

Yes, both ends looks like they should

How easy would it be to test one of the other cameras on the cable?

This is pretty easy and a good idea. I will try this tomorrow.

Can you use / borrow a cable tester to verify continuity?

Unfortunately i dont own one. Perhaps you can link to a decent cable tester?

Can you re-terminate ends to see if that eliminates the problem?

Allready did this and it did not solve the problem.