Component/VGA Video Interference

[zack]

Hey guys, I'm currently building my second GCP and I'm using a component chip with the VGA mod, and a 5" Dalian Good Display. I've been having issues recently with some sort of video interference. I've had interference before, but this is different. They are vertical lines that look like shadows, and they never move or change position on screen. It's very difficult to show on camera but here's a pic and video.

I've been trying to solve this for a long time. I've tried using different wires from the display to the component chip, adding grounded shielding, and completely rewiring the chip to the mobo, but none of that had the slightest effect on the interference. I outputted to my computer monitor and did NOT see the interference, so I thought it could be an issue with my screen. However, I tested the screen with a different (composite) signal and there was no interference. I've pretty much exhausted all options, so I really need some help. If someone could help me identify the type of interference and what might be causing it, I'd really appreciate any info anyone has. Thanks!

 

[megalomaniac]

GC video signal is dirty....
some monitors dont care and will look good...
some monitors will make it look like crap...

none of this mattered when GC was released during the age of analog TVs....a lot of "new" digital tuners cannot properly display RGBHV signal from GC and the bars you see are either a result of the GC's dirty signal or wires/shield/gnd etc etc...

logical testing:
1. compare the difference on that portable monitor between RGBHV 480i and 480p....you should not get noise on the screen with 480i...if you do not get noise with 480i then its your monitors tuner not compatible with dirty GC signal...


2. if you have an OLD OLD OLD CRT pc monitor then you can connect GC to that big fat tube...you should not get any noise on RGBHV 480i/p...this will validate your wiring/shielding/gnd

 

[zack]

Thank you very much, mega. I'll test around with it to see if 480i makes a difference. I actually don't notice the interference until swiss boots up, and I thought that was just because the menu was dark, but perhaps that's because the GC menu is in 480i?

Well anyways, whether it works in 480i or not, I'm still left with the issue of not being able to use 480p. If my GC signal is dirty, then I suppose the only way to truly fix the problem is to just use a different motherboard?

 

[megalomaniac]

GC starts up in 480i and swiss forces 480p....
since the lines appear with 480p, this shows your monitor cannot handle GC's noisy signal...

this is not a problem to the mainboard you are using...it is ALL GC mainboards...

you will need to find a new monitor compatible which will not display the noise...
the old dalian monitors use to be great with GC, but they have changed the display board which now causes the noise to appear...

 

[Bush]

Any way to filter the noise out?

 

[megalomaniac]

the signals going to the MX are digital...so no noise there...
any and all noise is generated by the official MX pcb only when using RGBHV....

i have not tested, but it is possible the HV side is introducing noise since those lines do not have any filters...

 

[zack]

Hmm, so it sounds like there are two options to get rid of noise. The first is to have just the right monitor that will accept the signal AND filter the noise, which might be difficult to obtain. The second would be to somehow filter the noise, which you say could be on the H/V sync lines. So possibly if that's the case, could we just slap a capacitor on the H/V and see?

 

[megalomaniac]

note:

i speculate it could be the HV signals...
if you try it pay attention to cap polarity


good luck

 

[zack]

Any idea what kind of caps to use?

 

[DuHasst0]

Don't mind me just passing through being a moron.

 

[zack]

Yes this thread is old, but I'm bumping because I solved the issue.
I was given the strangest advice - to run a PAL copy of Soul Calibur 2, then use the "Auto" button on the Dalian display which auto configs the image based on the video signal. POOF, all interference was gone. I was pretty surprised.
Something about the PAL signal or Soul Calibur 2 must enable the screen to properly adjust to the "dirty" GC signal and filter out the interference. Weird.