BVM-20F1E Monitor Cable

[MintyTheCat]

Hello all,

I picked up a BVM-20F1E Monitor today and brought it home. I have a few questions as I have not managed thus far to get stable video as yet:

1. I tried the Monitor out using a Megadrive 1 with the Pinout as:

http://www.gamesx.com/avpinouts/genesisav.htm

2. I connected MD pin 1 (Sync) directly to the BVM's Sync but got the wavy effect which means that it is not syncing.

3. I connected up the Green on the MD pin 3 to the BVM's Green.

4. I grounded the BNC Connectors and connected them to the MD's Ground on pin 4.

(*) I cheated and made a BNC Cable by simply cutting some old Cables in half and then stripping them to get at the copper wire inside the insulator as I happened to find many BNC Cables where I bought the Monitor.

Does anyone have a correct and known to work Schematic that I could see, please?

Also, do I need to generate the Sync Signal from the Comp.-Video from the MD on pin 2 using something like the LM1881 or can I simply use the MD's Sync Signal on pin 1 as I thought?

Cheers.

[Monstermug]

2. I connected MD pin 1 (Sync) directly to the BVM's Sync but got the wavy effect which means that it is not syncing.

Maybe a long shot but did you press the button from internal sync to external sync?

[Fudoh]

The Sync output pin on the MD only works if you put a capacitor (or a resistor and capacitor) in line with it. Sega forgot to include it in it's original design.

[MintyTheCat]

2. I connected MD pin 1 (Sync) directly to the BVM's Sync but got the wavy effect which means that it is not syncing.

Maybe a long shot but did you press the button from internal sync to external sync?

Good point - I will check. Cheers.

[MintyTheCat]

The Sync output pin on the MD only works if you put a capacitor (or a resistor and capacitor) in line with it. Sega forgot to include it in it's original design.

Good point and I did not add anything for the current level going in. OK, what values should I use for the resistor and cap. I dare say that a ceramic cap will be sufficient.

[Fudoh]

http://playoffline.wordpress.com/cable/md1rgb/

[MintyTheCat]

A quick update:

I have a Megadrive 1 hooked up and working correctly with my BVM now Many thanks for your ideas and comments.

It is very configurable and takes some time to adjust - thankfully you can name Channels