PAL Gamecube to JAMMA , SCART RGB

[s8n]

hi team , i am attempting to hookup a PAL Gamecube to a Jamma Cab.......i can get PS2 and Dreamcast running pretty well off the 1 Jamma Converter i built , but Gamecube tends to be a problem.......what im on about is the Video , it looks like it has a Grounding problem the image is feint and looks like it has a broken TV antenna its borken up.....ive seen this before with the DC and PS2 when i did not Ground it properly.


the Gamecube SCART cable is different to the Dreamcast and PS2........check here

http://members.optusnet.com.au/eviltim/gam...scart.htm#dcast


i have ordered a RGB SCART cable from PLAYASIA.COM so i dont have to crack open my Official......should be here in 4 days.


what can i do ?

any info is awesome

s8n

[s8n]

i forgot to mention i was 'referred' from KillerCabs.com by Mr-Megalo he mentioned possibly Lawrence or viletim could help with knoweldge.

[NFG]

I've never had trouble hooking up a GC to any kind of RGB monitor, though I confess I've never had an arcade monitor to use, just VGA/XRGB/TV/X68000/etc.  It's always worked perfectly.

My first thought it to blame the wiring - make sure your H/V sync lines aren't shorting out somewhere (like on the metal cover in the GC connector).  Experience has shown me that the GC is not using anything weird in the RGB, so I can only blame the wiring, but perhaps someone else has some advice.

EDIT: I've only ever used the digital port, never the analogue port which is apparently what you're trying to do.

[viletim]

How have you connected it? You can go straight from SCART to arcade monitor, you need some kind of circuit (usualy including an LM1881 IC) to get a useful sync signal from the composite video provided by the Gamecube.

And it is a PAL model isn't it?  

[s8n]

hi Lawrence and viletim , yes i do have a PAL GC and am using the LM1881N method

[NFG]

Ah yeah, if you're using composite video you will have to strip the vidoe and get a pure sync signal to use the arcade monitor.  Composite video only works on monitors with TV tuners in them.

[viletim]

Then is should just work....Check that the LM1881 is getting its +5v (with a multimeter), check that LM1881 ground pin are actually connected to ground....

Does the look different with the sync connected/disconnected? Are you sure you're using the correct wire for ground?

[s8n]

im pretty sure the LM1881N is getting power , i have built a Universal converter.......PS2 and Dreamcast both run pretty well off it but GC is problematic.

currently i have the GND generated from the LM1881N curcuit connected straight to the Video GND on the Jamma biscuit and then a wire from that to another GND pin on the Jamma biscuit.

the GND from the SCART plug is wired straight to the Video GND on the Jamma biscuit.

[viletim]

the GND from the SCART plug is wired straight to the Video GND on the Jamma biscuit.

The SCART plug has many pins labled as ground, but only or two of them (pins 17/18 usualy) will actually be connected to ground. At least this is the case with all of cables I own.

[s8n]

hi viletim my Official GC SCART Cable has no 18 pin but has a 17 pin , im going to attempt to use 17 as the ground.........be back later with results

[s8n]

viletim your a genius !!!  ................it was definitely pin 17 as GND...........i am going to do a little rewiring so it is Universal .......ie GC DC and PS2 on the one Converter.

nice work man !

s8n

[s8n]

thanx for the tips Lawrence and viletim ive posted a video on YouTube for a short time to show it working.


http://youtube.com/watch?v=faSSXx9rjLk


s8n

[NFG]

As a rule you should always connect ALL ground pins.  I never make connectors with just one ground if there are more available.  It's a good habit to get into, and would certainly have saved you some grief here.