I don't know. How to check if there are errors or how to watch what is happening?

Something is messed totally i'm getting "ssh: connect to host 192.168.0.102 port 22: No route to host"

Yesterday I have edited telegram file and have duplicated and edited some settings. I have duplicated damNmad's settings, set custom name and removed some info and break lines. Can that be the reason that OS is not loading? I have received test message several times and everything was ok. I have set the interval 1440min but today nothing. That was the message if it matters somehow:

Worker: 102
Current Hashrate:
System Boot Time: 2018-03-31 01:18:10
System Up Time: up 2 days, 3 minutes
Miner Uptime:
GPU Count: 1
GPU_UTILIZATIONS: 3
TEMPS: 45
POWERDRAW: 20.38 W
FAN SPEEDS: 0 %

Yes that was the problem at that time. I have removed my "customizations" and it starts normally and got connection. But miner still not working. Now is that:

Worker: 102
 Current Hashrate: 
 Boot Time: 2018-04-03 05:46:57
 System Up Time: up 7 minutes
 Miner Uptime: 
 Currently Mining: "ZEC"
 Reboot Required: No
 GPU Count: 1
 GPU Utilization:
 100 100
 Temp, Fan, Power:
 GPU 1, Target temp:  60, Current:  56, Diff:  4, Fan:  50, Power:  25 <br>
 
 
 
 
 
 
 Wed Mar 28 04:22:28 MST 2018 - Restoring Power limit for gpu:1. Old limit: 25 New limit: 125 Fan speed: 50

Hi, guys

I' using NVOC successfully for months but currently there is only one card left in the rig. I have removed the other cards and the miner didn't start. This card is with extender. Have tried to switch the PCIe slot but nothing.
The card is GTX1080 and is visible with nvidia-smi but the miner is silent.

Can you help me please?

Did you connect your GPU to the x16 (long PCIe slot) closest to the CPU? Also make sure the integrated GPU is disabled in the bios.