Problem getting jamma test rig 2 work on Scart TV

[JEDI]

Wussup

I have built my own supergun.
I

[Dave_K.]

You may want to ask this on www.gamesx.com as there are more people with scart TVs on that msg board (and people that have built super guns).  I don't understand the +5v to pin 16 (but everything else looks correct).

[canardo]

I am also suffering from the same problem

using a street fighter 2 rainbow hack board

one tv just displays a white ghost image (sony trinton)
the other the picture is all garbled (hitachi 24")

if anyone knows the solution please shout I was under the impression this would work if i wired the scart connector up as on chads website

thanks for your time

[Minwah]

I have a similar problem too...I wired up my ArcadeVGA to Scart using the same connections - the image is not rolling, but just REALLY black, can barely make out what's going on.

A few photos (running Windows) are here:

http://mamewah.mameworld.net/TV1.JPG
http://mamewah.mameworld.net/TV2.JPG
http://mamewah.mameworld.net/TV3.JPG

(Paste into browser)

I guess I've wired something wrong but what!?

[tom61]

Minwah, you probably need to buy the video amp on Ultimarc's site, your TV probably doesn't like the 1Volt Peak-to-peak output of the card.

Canardo, your TVs may not be compatable with the 60hz refresh rate that the boards output.

[canardo]

hmm 99% certain my tv supports 60hz (it works fine for the ps2 xbox etc)

thinking maybe I need to invert the sync signal

[Minwah]

Minwah, you probably need to buy the video amp on Ultimarc's site, your TV probably doesn't like the 1Volt Peak-to-peak output of the card.

Canardo, your TVs may not be compatable with the 60hz refresh rate that the boards output.

Thanks for the suggestion, but from what I have read Scart is designed to accept 1V (so 5V would be too high).  I'm not sure tho  

I think I need to wite the 5v with 100ohm resistor to pin 16 (blanking) as JEDI suggests...dunno what it does tho!  

[Cave]

I've noticed this pin connected on many scarts and it is also looped to pin 8, pin 8 switches tv to AV channel when it recieves 5v, not sure if this the problem but don't rule it out.

You could crack open a known rgb scart plug from ps2 or dreamcast to double check what pins are connected (except composite and audio pins obviously).

[tom61]

hmm 99% certain my tv supports 60hz (it works fine for the ps2 xbox etc)

If those are european ps2 and x-box, they output 50 Hz (at least they're supposed to anyway).

[canardo]

import ps2 and xbox cant be bothered to wait for european versions hehe hence i almost certaint they working on 60hz

have a jap dreamcast almost certain thats working 60hz (it doesnt even have a modem)

[Minwah]

My Dreamcast & GameCube scart leads can output at 60Hz if selected...

Good idea Cave, I'll have a look in my DC scart lead

[canardo]

Ok I have got mine working by ditching the scart socket I had and wiring it directly to a PSX RGB Scart cable( minus the audio pins) with the end cut off

the difference inside the connector is indeed pin 8 is conencted to the +5v blanking ground

also the grounds for each individual colour are not connected
and on the actual inputs there is a 100 micro farad capaicitor connected inline(to filter noise I presume)

also pin 18 is grounded

getting a slight problem with blue bleeding but other than that its a great pic and think this might be because my +5v is now going through 2 x 100hms worth of resistance.

Hope this helps you minwah

and thanks for the idea of opening a scart cable cave