Connecting a ZX Spectrum +2B to J-Pac

[chapas]

Hi,
I have a  J-PAC and a Hantarex Polo2 in my MAME cabinet.
I have made an adapter from Amiga 1200 (from Amiga RGB to VGA) and it worked great.
Now i have tried to do the same with my ZX Spectrum +2B, but it did not worked so great.

I have build the schematic i have found in this link, but for a VGA15 plug instead of a 9Pin VGA

http://www.worldofspectrum.org/forums/discussion/25849/redirect/p1

I plugged into the VGA of the J-PAC but could't 'hold' the image steady.


I'm i missing something here?

What's your opinion?

Thanks in advance,
chapas

[opt2not]

Check this doc out: http://mts.speccy.cz/doc/128_rgb.pdf
(read the Spectrum +2A/+3 RGB Differences section)

Correct me if I'm wrong, but it looks like the +2B doesn't put out separate H&V, from what I see here it only outputs CSYNC on pin 4 of it's RGB socket.
Doesn't the JPAC expect to have separate H&V sync from the VGA cable?