Camera problem Need Help

[vin2install 0]

Does anyone know what causes the video to contract like its breathing. And how to fix this. Here is the link to the video for it.

 

http://www.youtube.com/watch?v=5LrwWQXIXGQ

 

I don't know what causes this. All i know is it becomes really evident on 24vac. It doesnt do this right away though. Sometimes it ranges from couple minutes to a couple days before it starts.

 

Thanks,

Vincent

[vin2install 0]

Anyone???

[cglaeser 0]

Brownout? Thermal? Do you have a good power supply?

[vin2install 0]

Power supply is fine. This is on a test bench.

[survtech 0]

All I can think of is either a bad camera or a ground loop or some type of interference.

[cachecreekcctv 0]

This is just a camera with the ouput to a TV ? Or is this going through a DVR? Looks like something is out of synch.

[scorpion 0]

I will place my bet on a bad cap in the circuit.

 

Time to break out the freeze spray, and hot air gun.

 

 

Question:

 

How do you keep from rolling over your cat 5's??

[Soundy 1]

Sure it's the camera and not the monitor itself? Looks like it might be a bad power supply in the monitor.

[scorpion 0]

Sure it's the camera and not the monitor itself? Looks like it might be a bad power supply in the monitor.

 

That was my first guess when I saw the video.

 

I then thought that he could rule that out by attaching another camera, and having good video.

 

 

Could it be a bad circuit in the monitor, and only this camera "triggers" the monitor in to it's failure mode?

[vin2install 0]

Monitor is fine. I have both a CRT and upconverting LCD on my bench. No DVR. This problem has stumped me for weeks. I'm trying to figure out if the reason might be the Dual 12vdc/24vac board on the camera itself that is causing this. All i know is with a 12vdc input it doesnt do this.

[scorpion 0]

Bad bridge rectifier allowing ac hum?

[vin2install 0]

Bad bridge rectifier allowing ac hum?

 

hmmm That sounds about right. That could be the reason. I'll test that out and let you know the results.

[scorpion 0]

I am wondering if you can take an electrolytic cap, and put it across the power supply out to see if that would make a difference?

[vin2install 0]

I am wondering if you can take an electrolytic cap, and put it across the power supply out to see if that would make a difference?

 

Do you mean across the 12vdc that outputs into the CCD chip?

[scorpion 0]

Yes.

 

I do not know if one of the bridge rectifiers is leaking, and if the Electrolytic would flatten it out, or if there is a cap that is supposed to do that, and the cap is bad.

 

I thought by shoving a E cap on there that it would give you a clean picture, and then from there deciding if it is the rectification, or the filtering that is bad.

 

I want to say a cap is bad because of the "ripple" effect on the screen.

 

I notice that only the top part of the screen appears to do so. This is where I was thinking that it is a bad rectifier because when it travels in one direction through the bridge it is clean, and no ripple, but when it travels the other way it creates the ripple. The one side of the bridge being bad may allow some of the AC cycle to "slip" through. I would think that a good filter would clean it up some. The wave on the TV is so bad that it appears to be a failure with both the rectification, and the filtering.

 

If the cap cleans it up then it would save you from having to rip out the bridge rectifier.

 

Lick n stick, and you are done!

 

Also you can hit the bridge with a can of freeze spray. Perhaps it only "crashes" as the device heats up. This may explain why it works when you first plug it in then after a time it goes in to failure. As the bridge warms up it then "crashes".

 

The SMT's are a pain in the neck, but 3 feet lower!!

http://en.wikipedia.org/wiki/Surface-mount_technology