Norbain 16 Way Multiplexer

[Truss and France]

Installing a Norbain sixteen way multiplexer today (not my choice) and have the following problem if any one can help, all the pictures are fine on full screen but in multi screen mode three of the pictures are 'whiting out'. When I swop inputs the pictures are still the same, when the unit was first powered up everthing worked OK this has happened overnight. We have done a 'default' reset and it has not cured the problem. Spoke to Norbain who said it is either the camera lenes need adjusting or the unit was duff.

Just looking for ideas before we send it back.

Thanks

Kevin

[PJF]

Is it a Vista mux ?

Havent come across your problem before and I have fitted a lot of Vista Mux/DVR, each camera has an adjustable scope were you can increase/decrease the signal. Have a look and try adjusting it. It may solve your problem.

I cant see what difference it will make if viewing one or sixteen images, it could well be a duff unit

[ian.cant]

If its the same camera inputs then its likely to be the incoming signal in which case lens sounds favorite.

If its the same 3 inputs on the unit then it sounds like a defective connection on the board, ive had similar but not 3 at a time.....

[Guest Trulloman]

Have you checked your 75 ohm termination, if they are loop through coax. I had this the other week at a B&Q the staff had unplugged it from a monitor which was on a camera output and tried to use the cable for their TV aerial. The picture was fine on full screen but whiting out on multi.

[Doktor Jon]

If the pictures are fine on full screen, then it won't be the lenses.

Termination is a distinct possibility, as it sounds suspiciously like a signal level issue; try turning off any captions, and maybe disconnect all the camera inputs, then reconnect one at a time to see if any single (or group of common powered) camera(s) is causing a problem.

If the unit has unused looping outputs, try connecting a terminated test monitor to each duff channel and see if the picture appears different from that on the multiplexed display.

From your brief description so far, the multiplexer does seem to be suspect.

[Rich]

I would agree it sounds like a faulty Mux to me. You can try checking the termination on those ports but I doubt it will make a difference.

when you view the images in full screen you are not using the digital processing circuit used for the multiscreen view, my guess is that the block for those cameras is faulty, I susspect the 3 cameras are roughly in the same quarter on 16 cam split screen.

[Truss and France]

Thanks guys, for the advice.

Returned to site today to add more cameras, it is a Vista unit and the 'whiting out' appears on the 'even' number inputs 2,4,6,8, ect. which seems strange to me, anyway Im going to report it as a faulty unit.

Thanks again

Kev

[Rich]

It is most definately the mux, I am thinking back to the old robot multiplexers, the digital circuit processed half of the screen, in this case it sounds like the vertical right half for the first 8 cameras. Gerrit sent back