Video Going Crazy

HAi to all

This is samuel from india working in this field for the past 10 yrs ,i have handled various kinds of equipments.

I have a problem in one of the installation ie; the problem looks similar to a ground loop that is bars are running from top to bottom ,

i think for a ground loop to develop you need different sources of power at camera & Monitor.

Keeping this in mind i gave a single source of power to all the equipment that is C-mount,Speed dome cameras, the DVR & the TV.there are total of 8 cameras,out of which four are C-mount & four are speed dome cameras the c-mount cameras videos are coming fine while two speed dome cameras are fine but the remaining two speed dome cameras the video is not proper there are bars coming from top to bottom,i checked up & found that the cable of one of the camera are going beside power cable, thinking that this might be the problem

i relaid the cable so that there will be no interference. but still the problem existed.

I checked th power source it showed 250 Volts AC ,immidiately i put up UPS for protection ,still there is no improvement.

I am not able to troubleshoot the exact problem, i checked up whatever is possible from my side that is Linelock on ,others etc.., when i did the linelock ON the bars have stopped in the center of the video but didnot disappear.

Please help me out anyone

With regards

Samuel