hikvision cameras failed to work

[nyombi]

hikvision NVR and cameras failed to work once i reset it and only 4 show picture.i tried to reset it ,it shows the picture but after 2 minutes goes off and only remains 4 cameras work.please help me out to get sorted

 

[Phil]

Step 1 is always to bring all of your Hikvision devices up to the latest firmware revision available:
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