Williams joust won't dial in monitor

lostlumberjacks

Active member

Donor 2012, 2019
Joined
Oct 28, 2012
Messages
235
Reaction score
49
Location
Michigan
It's got a wells k4900 monitor that works in other games. I just put all new caps in it. I try to adjust vertical and horizontal settings and it just won't hold. I get it close and it starts going sideways or starts to roll depending on screen shot. I'm figuring its something on the game itself, because monitor is fine in other games. Horizontal seems to be worse. Also replaced the connector for rgb and +syncs. Also tried -syncs with no luck. Anybody got any ideas. Its very frustrating, Thanks, any help is appreciated. Todd.
 
WMS games used positive sync. You need both lines (H,V) to be on the correct input pin (don't short them together to the H sync input).
 
I'm figuring its something on the game itself, because monitor is fine in other games.

Sounds about right. Sounds like wonky voltage fluctuation on the CPU board perhaps, messing with the monitor control outputs. Voltages correct and steady? Check/clean all the connectors (plugs and board pin outs) on the CPU board? Make sure all the grounds are solid as well. I'd also check C81, C82 & C83 on that board.
 
Update: just before I started to work on it again, it went haywire. (Scrambled image) I ended up replacing all the 4 caps on the mpu, put on 3 all new connectors on mpu (male and female). And am still getting the same problem except now you can't even see the image. The voltages are good except the +5 is +4.89

I double checked monitor in another game and it works fine. Still having problems.
 
Check the video cable wires for continuity. I had one that looked just like that. Did everything you did and then just for grins checked continuity on the video cable. I found a sync wire broken inside the insulator about 3 inches back from the connector. Ran a new wire and it has been running fine since.

Also have you tried those boards with another monitor? I have a card table that is just the right height, so I set it up behind the cabinet and put the other monitor on it. That way I can pull the power and video cable from the good cabinet to the monitor in question without having to do a full swap. Less chance of busting a monitor.

ken
 
Back
Top Bottom