A little wiring help

[Brad]

Having put a substantial interface purchase on hold due to no money, I've been looking at wiring up the video out on a PC to the arcade monitor in my cab. Just can't wait anymore. I'm just after some reassurance on the wiring aspect though.

I have 2 molex connectors coming from the back of the monitor to the nanao cirsuit board.

1 molex = Red, Green, Blue, Black and Yellow

Is it safe to assume that these are Red, Green, Blue (RGB) Black = Ground and Yellow = H-sync?

The second molex connector is Red, Blue, Brown and yellow? Whats this one for.

I've wired up the VGA cable to the first molex but I get zero output on the arcade monitor. Can anyone give me ideas or pointers. All I did was unplug the first molex plug from the circuit board and wire the VGA cable into it. I just combined the 2 sync cables from the VGA cable together and connected the the yellow cable on the arcade monitor. This means of course that this connection now bypasses the nanao circuit board. Does this sound correct?

Brad

[menace]

what does your nanao achematics tell you about those pinouts?  Generally its safe to assume the RGB etc, but i wouldn't power it up until i knew for sure.  Also, a VGA cable has an h sync and a v sync separate, so try hooking the h sync of the vga cable to the h sync- of the board and likewise for the v sync.  My GO7 was particular on this point.

[Brad]

Thanks for the reply, my problem is I don't have a schematic for this board. It's a fairly typical Nanao KB240 331D from the looks of the model number though.

Brad

[bloodyviking77]

Hi,

If I understand you correctly, you are saying you have unplugged a molex connector somewhere on the monitor chassis itself and are trying to wire your vga output to that connector?

This might sound confusing, but you want to be wiring your VGA output to the connector on the chassis where the original gameboard connected. This might be (as on my nanao monitor) a little 5 or 6-pin header on the chassis, probably with each pin marked R, G, B, Gnd, Synch (or whatever).

Maybe try looking somewhere on the chassis (not the neckboard) for these markings.

good luck

cheers

[Brad]

Yes I feel like a bloody idiot now. I unscrewed the chassis from the side of the cab so I could actually see all the components and now I understand whats happening. I need to wire into the jamma harness side of the cabling so that the chassis is still used.

The plug is Red, Green, Blue, Ground and HD and VD

Seems straight forward but I get no picture output   Should I be using both HD and VD to hook up to the V-Sync and H-Sync on my VGA cable?

Brad

[bloodyviking77]

I'm no expert, by any means, but here's a few things to try:

1. Are you using an isolation transformer?

2. Make sure your monitor is actually powering up. To do this, turn off the lights in the room, then (with the monitor not connected to your PC) switch on the monitor. You should see the end of the tube near the neckboard light up and glow. (You'll prolly also hear a staticy sort of sound, especially when you then power off).

3. Once you've confirmed your monitor is powering up OK, check your wiring on your cable hack - you can certainly try separating out the H-synch and v-synch.  If you are using an ultimarc video amp, you have to cut a trace somewhere on the amp to split the signal. There's instructions on the ultimarc site http://www.ultimarc.com/vidamp.html

 Also, my monitor (a kaga KZ-18en-H) has little row of switches that lets you select what sort of synch signal the montior expects. Might be worth checking this on your chassis.

4. Also, what video card are you using? People around here will waste no time in recomending ultimarc's arcadevga, but other cards work too (just with more fuss). If you are using anything other than an arcadevga, you will of course need  special drivers.

 However, even with an arcadevga, you may need to boost the vga signal level. This will mean using a video amp (either build your own, I think there are schematics somewhere, maybe the pc2jamma page?) or buy one from ultimarc.

5. Finally, have you tried fidlling with the brightness pot on your chassis? (It might be that you just can't see the picture).

Other than that, might be one for the experts round these parts!!

Good luck

cheers
bviking

[Brad]

Cheers for all that info BViking. I finally got the sucker going yesterday.

It's actually weird but even htough the Jamma harness has both the VD and HD wires being used the PC output reused to work until I crossed the V-Sync and H-Sync wires on the vga cable and only connected them to the H-Sync (HD wire on the Chassis thereby not using the VD wire at all.

I get excellent picture on this thing straight away when emulating. What a treasure seeing Mrs Pacman running with no adjustment needed. Now if only I could get a desktop or frontend to display. Advance Menu refuses to display, I just get garbled graphics even though I keep telling it that I'm using an Arcade monitor. Once I start emulation it's fine but what a pain. I'll keep hacking away though.

Brad