So i picked up an old romstar burger time cab that was converted to an Arkanoid cab at some point in its life. It works and all but the monitor is 29 years old and looks like crap. i was looking at replacement monitors and holly cow are they expensive. I have a spare LCD monitor that would fit quite nicely into the cab. How easy would it be to adapt the RGB from the PCB to vga? Is it even possible?
Possible - VGA is technically an RGB signal. VGA signals run a higher sync, though, so you'll have to use an upscaler (unless your LCD supports 15.6kHz sync over VGA, but the vast majority don't and there'd be image quality issues anyway). The cheap solutions (you'll find plenty on ebay) are complete shit, but the decent solutions often surprise people with their price. Expect to put a couple of hundred dollars into it. In your case since the game is very old you'd want something that can preserve the scanlines that would be present on a CRT, so look into the XRGB series. Personally, for older low-res games I'd recommend bodging in a CRT screen from somewhere else. I know there's a guy who custom makes RGB harnesses for any old CRT tube, meaning you can take a composite-only CRT TV, salvage the tube, and use RGB video connections. I can't remember the name of the site; maybe someone else will.
Be aware that LCDs will have inferior picture quality and generally less flexibility with odd resolutions and refresh rates that some arcade games have. Midway has many games that run at 53hz like Mortal Kombat.
I figure it wouldn't hurt to try hooking it up and seeing if it worked. If it looks like crap or doesn't work at all then no loss. so i found a vga pinout diagram. Red Green Blue H-Sync V-Sync Grnd but Jamma has Red Green Blue Vid-Sync Grnd So i am confused. I mean, it should be as simple as hooking red-red green-green ect.. but what do i do with that Vid-Sync?
http://www.arcadespareparts.com/arc...rter/rgb_jamma_vga_converter_board/13052.html Anyone have any thoughts on this?
So i need to separate Composite Sync to H&V Sync. I cant seem to find a straight forward solution for this. Some people even say "Twist the wires together" but i'm not sure that would actually work.
You might need to build an lm1881 circuit to get vertical sync out of the composite. Personally I'd try hooking the sync on the Jamma connector to VGA horizontal sync and just see what happens. No responsibility here if the out-of-spec sync signal breaks something in the LCD, though - this is entirely at your own risk, and like I say it's very unlikely that your LCD will support it. You'll also definitely want to check out the voltage levels on the board, make sure it's in line with what the monitor is expecting (find a datasheet for your LCD). I don't know the board. You'd want to get some opinions before purchasing it.
If you must use a LCD display, get a CGA->VGA converter, that will also take care of the 15khz->31khz problem - just search for "CGA VGA" on ebay and you'll find something for around 40 USD. It will work, but it probably won't be pretty (compared to a proper CRT monitor).
Awesome. thank you very much. I'm trying to do this on the cheap, so using stuff i already have will cut down on the cost of course. Ideally i would like to just buy a replacement monitor but that is about $300 plus shipping. This way i can spend $35 on the converter and use stuff i already have. Thank you though. you led me in the right direction.
Why don't you just repair the monitor? It may be a simple fix, and there's no way a chassis should set you back that much.
Pardon the ignorance, but.. The chassis is the PCB attached to the monitor mount? (in this case, dangling from the mount). it seems whoever had this before me only used 1 screw to fasten the board. so after i remove it, what should i look for? Also, i have another arcade monitor sitting in my garage from my mame build 2 years ago. i would just swap it out, but the tube is damaged from when i hit it with my car.
I have one, they get the job done but there is some loss in quality of the image. I also find for Namco 246 games, I have to make adjustments to v&h pos of the image per game. Gets a little annoying after a while.
so i installed this yesterday. it works great, looks a lot better than expected. but even though it says "Chinese and English OSD" on the box and instructions. Everything is in chinese! I cant read a damn thing. Im trying to get the image to fit the screen a little better but i cont figure it out. do you know how to get it to english osd?
Sorry for the delay in replying. Yes, the chassis is the main board. You might be able to pick up a working replacement chassis and simply change them over. Repairing a chassis isn't advised without television repair knowledge - it's high voltage and dangerous. If the tube is damaged, it's no good. Don't forget there's a vacuum in there - you don't want it imploding on you! Again, the chassis might be, though.
In the menu options you can change it to english, I think it's the 3rd menu option. http://www.youtube.com/user/lukemorse1#p/u/5/d-kRPCmAt90 seems to cover changing the OSD language
Monitor cap kits a relatively cheap ($11 to $15 in most cases) and relatively simple to install if you can solder. The main thing is removing the cap from the tube, which holds very high voltage. You'll want to make sure to take the necessary precautions. If you're not comfortable in doing a cap kit, a tv repair or arcade repair service can rebuild it for you. Depending on your area, you might be able to find someone to do a rebuild from between $50 to $100.
