Permanent Black Line on screen!

[shobhitk 0]

Hi everyone. I have recently installed a 4 camera cctv system comprising of a CP Plus dvr alongwith 3 cp plus analogue 700tvl cameras and a 4th camera from Vintron having 1000tvl resolution. Initially i had purchased only the 3 cp plus cameras and all of them were working nicely as expected. a few days back i ordered the 4th camera from Vintron having 1000tvl. this 4th camera is also working BUT there is a peculiar problem with it. on the screen i can see a solid black horizontal line across the upper half portion of the video. it is pertinent to note that this is not the usual rolling horizontal lines which occur due to grounding errors. this one is a solid and permanent black line staying still in one place and only a single line.

to diagnose it i have done the following without any positive outcome:

1) i have checked with the dvr manual and it supports 1920 x 1080p resolution for previews.

2) i got the DVR replaced with a new one but the black line is still there.

3) i hooked the 4th faulty camera from the other 3 wires from which other cameras are working properly but the problem still remains.

4) i have a 10amp power supply so it should not be an issue.

5) lastly i got the 4th faulty camera replaced BUT the problem still remains.

 

yesterday i hooked the camera DIRECTLY to the tv and guess what, there was no black line issue! so i am guessing that there is some kind of dvr-camera compatibility issue.

 

I am confused. it would be so nice if someone could guide me with a solution.

 

PS: for reference i have attached a screenshot from the video of the 4th 1000tvl camera showing static black line.

 

Regards

[SunnyKim 2]

It is up to you to return it or not.

[shobhitk 0]

as i have already mentioned, i have got the camera replaced with a new one. but the problem is still existing.

1 important thing to note is that if i connect it directly to the tv then there is no such issue.

[SunnyKim 2]

Can you change the location or lighting environments of the monitor?

[shobhitk 0]

i have already checked it on 3 different monitors ie. laptop, smartphones etc. same result.

[SunnyKim 2]

Camera output is to be CVBS TV Signal, that is either NTSC or PAL? Right?

[shobhitk 0]

thats right. we have pal here and so both camera and tv is set to PAL.

i am confused...how could there be a permanent black line on the screen. everything has been replaced by a new piece including the dvr, and the camera. still same problem.

 

1 more thing i remember is that while connecting it directly to tv i used the BNC to RCA cable, while when i connect it through DVR i use the normal BNC-BNC termination.

all my other cameras are working normally using the bnc-bnc connection.

[SunnyKim 2]

BNC -RCA is just a physical interface change. Therefore, No change in the signal content. Can you see the differences from the Night and DayLight conditions?

[shobhitk 0]

nope same black line.

[SunnyKim 2]

It really beats me.

Switch the input port of your DVR for different camera, Ch4 camera into Channel 1 input port, vice versa.

One more question is that the picture captured has no color, in gray. How would it appear when color image is captured by the camera?, I am just wondering.

[shobhitk 0]

thanks for cooperating sunnykim. i tried switching the input ports but still no luck.

btw that is a colour image of a white wall. the black line appears even in color images.

[SunnyKim 2]

The reason i asked the question above was to check the video decoder of your DVR, since TV view is OK, as you said. Better buy a different model of camera. Anyway, it is a good puzzle.

[shobhitk 0]

once again sunnykim...thanks for taking the pains. i have decided to keep this camera. i would try to find a solution for this issue. meanwhile if anyone here has experienced such an issue and has been able to resolve it successfully then kindly share it on this thread so that i may solve it too.

[SunnyKim 2]

Please let us know if you finally solve the problem.

[the toss 0]

Hi everyone. I have recently installed a 4 camera cctv system comprising of a CP Plus dvr alongwith 3 cp plus analogue 700tvl cameras and a 4th camera from Vintron having 1000tvl resolution. Initially i had purchased only the 3 cp plus cameras and all of them were working nicely as expected. a few days back i ordered the 4th camera from Vintron having 1000tvl. this 4th camera is also working BUT there is a peculiar problem with it. on the screen i can see a solid black horizontal line across the upper half portion of the video. it is pertinent to note that this is not the usual rolling horizontal lines which occur due to grounding errors. this one is a solid and permanent black line staying still in one place and only a single line.

to diagnose it i have done the following without any positive outcome:

1) i have checked with the dvr manual and it supports 1920 x 1080p resolution for previews.

2) i got the DVR replaced with a new one but the black line is still there.

3) i hooked the 4th faulty camera from the other 3 wires from which other cameras are working properly but the problem still remains.

4) i have a 10amp power supply so it should not be an issue.

5) lastly i got the 4th faulty camera replaced BUT the problem still remains.

 

yesterday i hooked the camera DIRECTLY to the tv and guess what, there was no black line issue! so i am guessing that there is some kind of dvr-camera compatibility issue.

 

I am confused. it would be so nice if someone could guide me with a solution.

 

PS: for reference i have attached a screenshot from the video of the 4th 1000tvl camera showing static black line.

 

Regards

 

 

It's a noise problem on the cable. You are getting a parasitic harmonic of 50 or 60 Hz (depending on your supply)

[shobhitk 0]

i dont know why but toss i also have a very strong feeling that this has something to do with noise / interference on the 50 hz supply.

BUT the thing is that all the other 3 cams are working beautifully. also i have my dvr properly grounded too.

as i have told earlier, i have tried connecting it in place of the other 3 cameras but the black line always comes up.

 

1 more thing...it might not be the noise issue in the power supply because i used the SAME power supply to connect it directly to the tv and there was no issue of black line.

[SunnyKim 2]

As TV-View is completely OK (No Black Horizontal Stripe),

the output signal from the Sensor and image signal processor chip of the camera is free of such issue. That's why it puzzles me.

[shobhitk 0]

sunnykim can it be because of low bitrate setting on the DVR? because this faulting camera is of 1000 tvl. currently it is set to CBR - 2048 kb/s, also there is a setting of 'I Frame Interval' which is set to 2. i have no clue as to what does this setting do. any guesses?

[SunnyKim 2]

1000 TVL sensor means one of the newest sensor. It is highly likely to carry the one of the newest and most advanced image signal processor as a back end chip of the analog camera.

 

Your DVR is supposed to compress the live video data from each camera, correct? Constant Bit Rate 2 Mbitps per each channel presents a very good recording video quality for analog camera.

But note that I frame takes a lot of bits for compression. If you set I (intra coded) Frame interval to 2, it can easily reaches over max assigned (2 Mbps) bit rate. So the Compression chip would try to reduce the bit rate for meeting the budget. leading to such Black Stripe. You can relax to 25 frame interval. Let's see!!

Is it true that the picture is taken from play-backing of your compressed bit stream from recorded file? The TV view is being done on the live pre-view directly from camera? Then the problem can be explained. But this does not explain the fact that other cameras are OK and fine. Other cameras are assigned to other bit rates?

[shobhitk 0]

yes it is the newest sensor, 1/3 SONY Exmor CMOS Image Sensor to be specific.

 

sunnykim only 2 options are given for the i frame interval ie. 1 second OR 2 seconds. currently it is set to 2 seconds. so should i switch it to 1 second? would that relax it to 25 frame interval as you have stated?

 

and that picture has been taken from the live preview THROUGH the dvr and not from play-backing of the compressed bit stream from recorded file. nevertheless, i guess compression is still being done as it is being played through the dvr.

 

and yes the TV view is being done on the live pre-view directly from camera. the camera is connected directly to the tv by BNC-RCA cable setup.

 

and lastly no sunnykim other cameras are not set to other bitrates. all the cams share exactly the same settings. BUT the other cameras are a mixed lot of 650 tvl and 700 tvl. none of them boasts of the 1000 tvl resolution.

 

i guess i have answered all your queries

[SunnyKim 2]

When I said "I" frame interval to every 25 Frames, that means one I frame per every second, as PAL has 25 frame rate. Targeting 2 Mbps is for a good video quality for recording, and should be OK for D1 size video data from an analog camera. You can try one I frame per two seconds but that would not make differences, I guess. I am quite puzzled because clean on TV means the camera is innocent, though a TV has a good video decoder in side. But such black stripe can not be cured, even by the best TV in the world.