Daytona USA Monitor Sync Issue

Arcade1VA

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I finally got my Daytona USA Twin put to gether and fired it up. The WG 25K7401 monitor in it will not sync at all. It is very bad and no amount of adjustment will make it better. I put a new cap kit on it before I fired it up. The game will play "blind", but the sceen is so out of whack you cannot make out anything. I have not worked on too many of these monitors, so I was wondering if anyone has seen this issue and knows how to fix it. I am making the assumption that this is a sync issue with the monitor only. The main board stack was tested and known working when I installed it, so I am ruling it out. Since info on these seems to be limited, and the schems/manuals aren't that great, if anyone could lend a hand I'd appreciate it as I would like to eventually play this thing...
 
Lets see a pic of the video connector how it is connected to the chassis...
 
Isn't a K7400 standard resolution, and Daytona USA medium resolution? I assume the monitor doesn't look original? I've seen lots of times where someone will throw any monitor in a cab to sell it "complete".

DogP
 
I tried...my digital camera blows...the monitor looks as tho it has never been removed...but it is hard to tell...I only pulled the chassis to cap it. It is marked P763, but I cannot find out exactly what it is as any other stickers are now missing. There is a sticker on the cab that shows a 25 to 15HZ jumper for a dual res monitor, but I am not seeing anything like it, although the access is very limited to the back of the monitor
 

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Look at the back left edge of the chassis. There should be a sticker there. It will say something like WGMxxyy-. xx is the size of the tube, and yy is the model:

74 = K7400 standard-res
75 = K7500 medium-res
20 = U2000 standard-res
50 = U5000 Dual-res
 
Oh, now that just sucks....Couldn't I pull the 7400 and put a 7500 with a matching yoke? The tube could care less, correct?
 
that kinda figures that's one of the first stickers to fall off i swear. Not sure on the swaping it might be easier to either find a whole monitor or a game like Virtua fighter that has one in it and swap. Good luck. Nanao's are out there and are switchable too.
 
Oh, now that just sucks....Couldn't I pull the 7400 and put a 7500 with a matching yoke? The tube could care less, correct?

not entirely sure why the hell someone would drop a CGA monitor in there, but whatever.

yes, I believe the tubes were the same on those, but you need a K7500 yoke, or alternatively you could use a U5000 chassis and run it on 24k (not have to swap the yoke, yoke was same on U2000, U5000 and K7400 -- basically any of the WGs that ran 15k)

if you want I got some basically unknown condition U5000s (from a big monitor parts lot)... if you're handy with fixing that sort of stuff I could probably help you out there.

if you want I could try testing them, see if any of them work and what may need to be done on them. I'm sure I at least have one that works.

unless you're interested in outright trading your K7400 for one of my existing U5000s (that are working on location). I have one application where all I run is standard res.
 
Well, if you have another standard-res game nearby, you could try getting them close and hooking the other game up to this monitor. If it syncs, then you know for a fact the monitor is good but wrong for this game. if it doesn't sync, it could still be the right monitor and it has problems...
 
I was actually thinking of taking my test rig and hooking it into the back of the game as I currently have a standard res. board on it to see what it would do, so I'll know shortly what I have to work with.
 
Well, no luck getting my test rig to sync...as a matter of fact, I can't get the remote board to even work...does the 7400 only use composite sync, as the board I am using has separate horizontal and vertical sync wires.
 
there's separate syncs on these, I'm sure of it, I know one says V-S. it's not labeled on your board?

cause I used to accidentally plug the comp sync into the wrong pin, and then I'd start turning sync knobs like an idiot until I figured out I was a pin off. lol

maybe dig up the manual at WG's site in the support section. but there's 3 separate pins for sync on these, most likely Comp, V-sync, and then H-sync, in that order.
 
Yes, if you are using a JAMMA or negative sync game to test it, only hook up the negative horizontal sync...
 
I have a Cinemat System board on my test rig, uses both horiz. & vert. sync wires. No luck...I no longer have any working JAMMA boards.
 
does your chassis look like this one exactly?

http://www.homearcade.org/BBBB/mon70.jpg


If so then you have the 7400 if there's some variations then you prob. have the 7500.

And damn man you really need to find a junky Jamma board to same as a test board find something that partially works just so you can use it. That'll save you countless hours while you learn the monitor repair trade.
 
Well, it does look exactly like that, although I don't know what the differences are electronically as both look almost identical according to the manuals. The chassis that is in the machine now has a sticker marked P763, which is the K7400 deflection model, so that is what makes me think it is the standard res. and not the required medium res. That being said, I have absolutely no use for this if it is infact a standard res. chassis as this is the only game I have (other than the Indy 500) that has a 25" monitor. So I'll need to find a working med. res chassis and yoke, and sell this one (or trade it).
 
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