I'm working on a SNES to Jamma project and I'm trying to get the display working on the arcade monitor. I am able to get the picture up and running on the arcade monitor, but the picture is very faded and messing with the r,g,b + brightness dials won't help get better colors. I'm using the original SNES and not the snes2 version. Does anyone know how to fix this problem?
Throw a 220uf cap into each of the RGB lines, that should cure you.
does it matter what type of capacitor it is, like if it is a electrolytic?
Electrolytic is just fine. Make sure you connect them up the right way around though! The negative side should go to the arcade monitor, and the positive side should go to the SNES.
The capacitor just blocks the DC voltage that is on the RGB lines. This voltage confuses most monitors and leaves a poor picture.
I added the 220uf capacitors to each of the r,g,b lines and it still didn't work. I'm getting the r,g,b signals from the a/v pinout. 1-Red, 2-Green, 3-composite sync, 4-Blue, 5-Ground. Could this be the problem? Should I be getting them from off a chip on the motherboard instead?
No, those pins are simply connected to the motherboard. That really should have done it, does the monitor work well with the actual arcarde board? Id almost bet a dollar that you just wired the capacitors wrong, check your wiring, make sure they are 220uf, and make sure you have the right direction.
the monitor works well with the two arcade games I have, Street Fighter 2 and Street Fighter Alpha 3. So I know it's not likely to be a problem with the monitor. I have the capacitors all wired correctly with the neg side going to the monitor. I'm using a 220uF electrolytic capacitor (axial leads and 35v max) each for the r,g,b lines. Got them from radio shack part#272-1017. Do you think I didn't get the right kind of capacitor? Also, has anyone here actualy ran the r,g,b from a SNES to an arcade monitor before and gotten a decent picture?
I finally figured out what was the problem!!!! And I feel really stupid too :( !! Becuase I have only 2 jamma fingerboards and they are both already been used, I had solder the rgb lines to one of the fingerboards that was already being used for my gba2jamma project (actually both fingerboards are being used for the gba2jamma as I've made 2 of the devieces so far). I figured that if the gameboy advance2jamma thing was off, then there would be no problem... but I just realised that it IS a problem as its circits would still effect the r,g,b signals. So after I noticed what the problem was, I unsolder the wires from the fingerboard and cut+resolder the r,g,b sync+gnd wires connecting to the monitor board and ran the snes with no problems! I also had success with getting rgb from my genesis (the mini redesigned one :D ) to display on the monitor. By the way, I tried both the snes and genesis without the capacitors and they both worked fine (even worked better without them!).
Well, I'm glad this problem is over with! And I'm gratefull for all the help from you all! Even though the problem was because of my stupidity.
Hey good job! Yeah that would be it too.
If you want to keep the two projects from interfering with each other, use a bunch of diodes on the connectors so that the appropriate signals will go outwards, but not inwards (or vice versa). You still might run into problems having them both hooked up but it could save a lot of swapping. (I hate swapping cables!)