Light Gun Flash On Arcade Monitor, Disruptive...

[shan1784]

Hey Everyone,

I'm waiting for my replacement Aimtrak to come in so my son and I can play some lightgun games but while we are waiting I loaded some new games onto my cab...

I noticed while my son was playing Area51 with the trackball that when he would shoot the screen would almost roll vertically.. I expected for there to be a real quick flash with each shot but this is a pretty disruptive screen flicker / roll...

Is this normal or can it be fixed... I thought it may have something to do with the refresh rate of the monitor but wasn't sure.. I'm not a hundred percent on the details of my monitor but some general ideas on what can be done to fix it would be great...

[bkenobi]

A white flash is normal.  Anything else is not normal.  Can't say why it's happening unless you are not matching your monitor's refresh rate for some reason.  Good luck!

[shan1784]

Yeah, I dare say this isn't normal... I'll have to take a video of what it's doing... I didn't know if I would need to adjust the vertical roll or something...

[RandyT]

I didn't know if I would need to adjust the vertical roll or something...

That's where I would start.  It sounds like it loses vertical sync when it gets that spike in brightness.  If the adjusting the vertical doesn't help, try dropping the brightness or HV a little.

[shan1784]

will do, thanks for the advice...

[shan1784]

I've tweaked this quite a bit and can't get it to where I'd like it... Playing with the v sync helped a little but it still seems to jump more than it should... I've looked at my monitor and it looks like I can run it at 15 or 25 khz... Right now it's running 15 khz but when I try to run it at 25 khz it's all jacked up.. At 25 khz I can't get anything to show up no matter how much I tweak the control board...  I'm running the monitor through a jpac as well so I don't know if this combination is what is causing this jumpy screen game play or what... I looked at the jpac and it has jumpers on the board for 15, 25, and 31 khz... Not sure what it's set at right now...

What I'm thinking is the monitor is running at 15 khz so maybe being able to bump it up to 25 khz might help the situation as it will be able to refresh quicker... Does that sound logical? Does anyone know how to setup the jpac for 25 khz?

[shan1784]

Well, I just ordered a Cap Kit for my monitor so I'll see if that helps...

[shan1784]

Well I installed the cap kit for my monitor and nothing blew up... I think it made a difference but the screen flicker is still there a little bit... I've got some before and after vids of what is going on...

Take a look and tell me if I'm making to much of this or if it really is annoying...
(video was taken with my iPhone so quality is not the best)

Screen Flicker In Area 51 - before cap kit install



Screen Flicker In Area 51 - after cap kit install

[Malenko]

does it happen on any other shooting games or just area 51?

[shan1784]

It does it on Area 51 Zero Point, and Goul Panic...

[bkenobi]

Yeah, that doesn't happen on my TV running via S-video.  I can't help you fix it (no clue...), but I can confirm that is not normal on my setup.

[shan1784]

Well I made some headway on this issue... I tweaked the brightness, contrast, and turned on triplebuffers... It now only flashes with each trigger pull rather than flickers...