I'm in the process of consolizing a Neo Geo MVS, the joysticks work, but there is something wrong with the picture?! I tested all solder joints, measured everything with a multimeter.... i don't get it, everything seems to be connected right. I am located in Europe, so i use SCART and direct RGB. Is the board busted? maybe someone here can help me. Thank you very much! http://www.youtube.com/watch?v=TF7urjk9iW8 (turn the volume down first, it may be a little loud, sorry)
wish I could help you but mine's running through s-video so we don't have scart out here. Does the blanking signal pin have the correct voltage?
Arcade RGB levels are a lot higher (1 to 4.5Vpp at 1K ohm) then what scart TVs are used to (0.7Vpp at 75ohm). For a start check to make sure you have wired up ground to at least Video Ground (pin 18). Also make sure you have a 100 ohm resistor between +5V and Pin 16. If you have or it doesn't make any difference then try putting a 300ohm resistor between Composite Sync and Pin 20 of your SCART cable and see it that improves it. If the colours are still too bright put 75ohm resistors between the Red, Green and Blue pins. Also don't connector audio from a Supergun to a monitor unless you have attenuated the audio so there is no chance of you blowing your TVs amp. If possible use a seperate speaker. A lot of build your own supergun pages are pretty poor when it comes to SCART and arcade monitor levels...
Looks like all my Genesis-s (Geneses*) do when I hook up a shit chinese power supply. I second the notion of a simple signal output level, however.
done all that, its still the same. i wish i had another supergun and another arcade board for testing.
Try on another TV to see if it's a problem there, the fault looks either like a grounding issue (make sure you do have good grounds, connect up all the grounds on the board to the PSU and make sure the SCART cable has Video Ground connected to Video Ground on the SCART and for luck stick a ground to the Audio Ground) or a level issue. Stick a pot of at least 1K (try a 5K too), between the Sync and SCART and do the same for the R, G and B lines. Adjust with the aid of a multimeter to see if improves the picture.
Is your scart cable shielded? I'd check the ground pin in particular and that you have 21 (the plug shield) connected to ground as well I have had some success removing unused pins from home-made scarts. Assuming it is the standard home-made kit, they should just clip out If you have ferrite beads to hand, I'd put one at either end of the cable Have you seen mmmonkey's guide to MD/Neo-Geo Scarts? It may help... http://www.mmmonkey.co.uk/
tested on 2 other TVs (all the TVs support RGB, says so in their manual, and i tested it with other input sources) still the same. i will take the whole thing apart and start from scratch. thank you all! sincerely, the arcade noob ^^
You know, I have no idea. Some of them just have a nice white line that goes up, and it looks like crap. The best one has a bad audio hum. The rest jump video every 10 seconds, it'll scroll up. Maybe there's something wrong with those particular systems which is being multiplied by the crap adapter. I've made a separate thread for this matter.
If the power supply is unregulated or has poor filtering on the outputs then you could have strange effects ranging from audio hum to picture problems to outright crashing/dying. It's more likely that you are overdriving the inputs on the display or your display doesn't like the sync rates of the Neo Geo board.
its alive! its working! the problem was: the diagram i was working with was not correct. now that the tech side is perfect i can move on to finalize the casing.
diagram? jamma to scart is just like..straight wires isn't it? anyway the case looks cool from what I can see in the video. Mind posting some nice pics of what it looks like?
the diagram on the website had some contacts on the jamma pinout labeled incorrectly. so true, oh so true...
oh I approached the whole building of a supergun thing differently. I started with the angle of "how the f#$% does it work?" and from there managed to make a working one on the first try. Luckily it's a pretty straight forward piece of hardware. Also what are you using for a power supply?
yes, and the sync pin was labeled as on the upper connector and the blue pin on the lower, hence no blue. pretty f'ed up diagram...
