Troubles with Sony PVM 20M2MDE and MegaDrive 1

[armorharmer]

Hello Folks,
My name is Strahinja, I'm a Linux System Administrator, a rockabilly double bass player and I love vintage games. I'm also a proud owner of Sony PVM 20M2MDE 20" which I picked up for 100e.
I bought BNC converters and a man made me a SCART to RGB + sync cable, which is plugged into female-female scart on one side and the console on the other side. So that would be my setup.
Playstation 1 works great and the picture quality is really amazing.
Two days ago I bought first edition of MegaDrive (Made in Japan) with SCART, but when I plug all as I did in a case of playstation I got some strange results. I will post some pictures to make this more clear. You can see them in this gallery http://imgur.com/a/3ZqOV
I would really appreciate any help.
Thanks in advance!
armorharmer

[kamiboy]

Looks like the SCART cable is missing 220uf caps.

[armorharmer]

Looks like the SCART cable is missing 220uf caps.

kamiboy, thanks for the reply!
Any quick solution for me? I am noob regarding to electronics, but my father is sodering guru, so I'm lucky. I just googled, I can find them in Serbia, but with how many Volts? And where to soder them? I would be more than a happy with some guide if possible.
Thanks again!

[blizzz]

This is how the cable should look. The caps are in line on the color lines.



Edit: Forgot to insert the image... lol

[armorharmer]

This is how the cable should look. The caps are in line on the color lines.



Edit: Forgot to insert the image... lol

It's okay blizz, I used my imagination, but scheme didn't look anything like that on a picture. I would really appreciate a real picture of that setup since we don't really now where to soder caps and how it should look.
Thanks blizz

[kamiboy]

kamiboy, thanks for the reply!
Any quick solution for me? I am noob regarding to electronics, but my father is sodering guru, so I'm lucky. I just googled, I can find them in Serbia, but with how many Volts? And where to soder them? I would be more than a happy with some guide if possible.
Thanks again!

Usually ~6.3V caps are used. Make sure they are small enough to fit inside the scart housing. As you can see on the diagram they have to be soldered on pin 7, 11 and 13 which carry the RGB colours. They should be soldered with the positive leg connected to the respective colour line coming from the console and the negative leg to the scart pin. The 75ohm resistors should not be necessary.

[Fudoh]

The 75ohm resistors should not be necessary.

On the MD1 ? They certainly are. The peak voltage levels are too high without them. I would usually even recommend a little higher ones (100-120 ohms). On video processors you're running into constant dropouts if you don't use resistors in the RGB lines.

[kamiboy]

Interesting, I do not think that I have them in my cable. I cannot be arsed to check though. In that case you should just add one leg of each 75ohm resistor to each colour line and connect the other leg to the positive leg of the capacitor.

It might actually be easier if you just order a new proper SCART cable meant for a NTSC MD from one of the many websites that make them. There is not much room in a SCART housing.

[armorharmer]

The guy that sold me this MegaDrive and also the cable had it working on his TV sets (regular not PVM).
And yes, this MegaDrive is modded with a little switch between PAL/NTSC. On both positions it gaves the same results.

[kamiboy]

Open up the SCART housing and take a picture of the insides so we can be sure of what we are dealing with here.

I am bit unclear myself as to SCART cables for NTSC vs PAL systems. I believe the ones for PAL systems lack 220uf caps, but have 75 ohm resistors and the other way around for NTSC system cables.

But whatever the case, it should work on the PVM if it worked on a consumer set.

[blizzz]

I am bit unclear myself as to SCART cables for NTSC vs PAL systems. I believe the ones for PAL systems lack 220uf caps, but have 75 ohm resistors and the other way around for NTSC system cables.

That only applies to the Super Nintendo. You can check the other cables on this page: http://members.optusnet.com.au/eviltim/ ... escart.htm

[armorharmer]

[alamone]

No caps on the RGB lines, I think they're required for PVM. I recall having a similar problem with the colors.

[kamiboy]

Yeah, just as I suspected, you need to solder a 220uf cap between each of one of the RGB lines, that will fix you right up. Nothing to it.

[armorharmer]

Guys,
Can someone take a picture of their scart opened so I can see caps?
Regards