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Re: cctv camera no image



>That is incorrect.  At the BNC connector you will >typically see about 1V,
P/P.

Trying to explain that to the OP not knowing what meter or setting he has
available is tough, especially since he was told by one poster he would not
see anything. On some color cameras I have seen it as high as 1.4 volts peak
to peak. We use a meter that costs more than half a grand to measure CCTV
problems. I am sure you've seen one or maybe had one. It allows you to focus
the camera just by looking at the numbers alone without ever having to see
an image. There are other useful measurements there for finding problems
with video as well. Maybe you could figure out a way to make money renting
them to customers doing their own large conventional CCTV installations?

<robertlbass@xxxxxxxxxxx> wrote in message
news:1193872093.427755.68150@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> On Oct 29, 4:53 pm, resisto...@xxxxxxxxx wrote:
> > On Oct 29, 2:21 pm, e.dav...@xxxxxxxxxxxx wrote:
> >
> > > What could be the cause of a cctv camera suddenly having no image?
> > > There is still a power LED coming on, but no signal coming through.  I
> > > have tested the voltage on the BNC output and it shows 0V.
> >
> > Well you should not have any voltage on the BNC connector.
>
> That is incorrect.  At the BNC connector you will typically see about
> 1V, P/P.
>
> > You should
> > have 2 conductors for power. But if the led is on then you have power.
> > So either the BNC end went bad especially if it is those junk twist on
> > ones
>
> That is also incorrect.  Twist-on connectors have been in use for
> years without failing.  You have to strip the cable correctly to use
> them effectively.  Soldered or press-on types are better for high def
> signals.  However, very few CCTV systems are HD.
>
> > or something blew the camera. I have had that happen twice in the
> > last couple weeks
>
> That or a loose connection are the most likely culprits.  If there are
> other, functioning cameras in the system, swap the bad with a known
> good one.  First try swapping BNC inputs at the DVR or monitor end.
> If the problem remains the same the DVR or monitor has a problem.
> This isn't as likely but it's the easiest thing to check so do that
> first.
>
> If the problem follows the swapped input, restore it and swap the
> camera with a known good one.  If the problem stays the same it's a
> bad cable or BNC connector.  If the problem follows the swapped
> camera, then the camera is at fault.
>
> Regards,
> Robert L Bass
> www.BassBurglarAlarms.com
>




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