Computer monitor problems (converting to sync-on-green)

[Hoagie_one]

I picked up a couple older 21 inch computer monitors.  They use the old BNC video connectors.  Now on these two, they only use three connectors instead of the full five.  They just use the Red-Green-Blue.  No v-hold or H-hold.

I pluged in my 5 BNC connector into them, as I was told they it would work in a 3BNC monitor.  I get signal but it is all static and jumps all over the place.  THe v-hold and H-hold dials on the front dont help.

My question is, doesn anyone know what I am doing wrong or are the monitors just fried?

[dabone]

With only three connectors it's probally a sync on green monitor.
What kind of monitor is it. Manufacturer/model number.

If it is a sync on green just tie your sync in the the green signal.


Later,
dabone

[Hoagie_one]

OK, so what your saying is that i should just cross the green, and the two sync cable's together?

[Hoagie_one]

i just found this circuit diagram to alleviate this very problem, which basically says you cant just connect the cables.

I know little about circuits, but i do know that if i can get this working, ill have two 21 inch monitors

[whammoed]

Hmmmm,
I have in my hand right now a vga (db15) to 3 BNC (RGB) adapter.  Just remember having it at the office here.  Has HP on it so I assume it went to some HP monitor.   Wonder if it would work for you?  Have no idea if it has any circiutry in it.

[whammoed]

Here is a link to one:
http://logicbox.zoovy.com/product/CABVIDEO

[whammoed]

I think this will work for you if you use a video card that can send sync on green...I found this info.  Seems like an alternative to the circuit idea anyway:

The HP A1097 and A2094 monitors only support the "sync on green" signal specification. In other words, unlike the VGA standard which provides a special signal for horizontal and vertical synchronization, the monitor depends on a synchronization signal that is overlaid onto the green signal cable.

Unfortunately, most PC graphics cards do not support this type of synchronization. To my knowledge Matrox used to make a card that would support sync on green, but most if not all of the current PC graphics adapters do not support this. You should consult with the vendor(s) of your graphics cards for this information.

If you do find a graphics card that will support this type of sync, you will need a VGA (15-pin D-sub) to 3-BNC connector. Also, this monitor will only support a single video mode, in this case, 1280x1024 @ 72Hz.

[Hoagie_one]

thats my problem, i want to use any video card adn have it work.

thus the adaptor.