Yes, I did manage to fix this. My issue turned out to be a result of me using a cheap jamma harness. I ended up buying one from twisted quarter and boom the problem was solved! Those converters can have issues, so maybe building a jamma setup without that converter might be worth a try. Hope this helps!
- Thread starter MK4Arcade
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kinooshi823
Professional
I've re-bought a couple of jamma harnesses from amazon and then I bought another gbs 8200 and now I have another lcd converter coming to try this issue. But if it's the harness then damn, maybe I should have bought that harness from twisted quarter. Only thing though is that the cheaper harness came prepped while the ones from TQ aren't that's another issue there unless they were willing to prep them.
I'm pretty sure it's either the jamma harness or converter you are using. I've had sound issues on MK boards as well due to the harness not being wired correctly for that -5v that the sound needs. Also, those cheap harnesses seem to have a different gauge and feel to the wire....it feels cheap tbh. I made these mistakes when i was barely beginning to learn about the hobby. You've tried to adjust the settings on the gbs correct?
kinooshi823
Professional
So since last week, I have repurchased another gbs-8200 and no change. I then went and bought another lcd control pcb for the monitor itself and again, no change. I have an ossc coming in the mail and I am curious to see if that would work by using the hdmi port on the lcd board. If not, then I give up, lol. I mean other options would be of course to get the harness from TQ, but it comes unprepared and I would have to clamp the connectors myself and redo the whole wiring. So that would be a $40+gamble over all. I have included pictures for you to see. The pic on the left is the board on my supergun running on my tv. The other is on my arcade1up and there's clearly a difference.
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channelmaniac
Professional
MK4 is different in that it uses a video amplifier chip that requires -5v to output video properly.
kinooshi823
Professional
That would be the reason why when I hooked up my MK4 board, it looked normal. What would be the cause of the MK2/MK3/UMK3 boards being dim? is there something I am missing?
channelmaniac
Professional
How dim? I normally have to crank the brightness up on my monitor when working on MK1 boards, but MK2/3 are just fine. Check your video adapter settings and make sure you have a good video ground connection between the PCB and it.
kinooshi823
Professional
Pic on the left is the board hooked to my supergun. Pic on the right is the board hooked into my arcade1up converted into a jamma arcade. All grounds have been accounted for many times. I tried different spots same result. My MK2 and MK3/UMK3 boards are the only PCB's in my collection that has this issue. I've repurchased the GBS several times now thinking it is that, same result. I've repurchased the same LCD board, same result. I've purchased a few jamma harnesses' same result. I even bought a new power supply, same result. Only thing I did not do is buy a new jamma harness from twisted quarter which would be another gamble. I even tried the OSSC I got this morning since the lcd board supports hdmi, I got a dimmer result. I've played with the settings on both the LCD control and the GBS and nothing. I am beyond stumped here.
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channelmaniac
Professional
There's no standard on video output levels in the arcade world. Some boards just output video that's higher voltage than others. We're talking tenths of volts here...
kinooshi823
Professional
So I assume that means that it is something I can't control?
I will say that before I bought this UMK3 board, the seller showed it to me working on a CRT and it displayed fine.
I'm aware getting a CRT may fix this issue but to fit that into an arcade1up, it's a challenge. Maybe a Wells-Gardner LCD could fix this.
I calibrated voltages and checked everything with a multimeter, not much difference as I didn't want to push the voltage.
I really wanted to solve this, but I also didn't want to dump a ton of money since I have gone over budget with this. $150 project turned into over $400. I guess I may have to live with this for now.
channelmaniac
Professional
Nope.. nothing you can control... Unless the converter lets you tinker with brightness and contrast.
kinooshi823
Professional
The gbs-8200 does let me control brightness and contrast, and so does the LCD board. But tinkering with both of them brightens the image but doesn't brighten the backgrounds in the stages which I am not sure if that makes sense. Like it brightens one layer but no all of them.
