I'm having an issue where I have vertical screen rolling on some games. It happens on the Konami logo on Rondo of Blood, the second stage of Space Harrier and when I re-enter the first castle on Mysterious Song. It is a DuoR from doujindance. I'm using a Euro scart cable into a scart to component box. My genesis and SNES don't have this problem. Any ideas? Thanks.
Does this only happen on bright screens like when the Konami screen turns white?
A white screen will do it for sure but it doesn't have to be. While in the 240p test suite the "white & RGB screen" test will do it every time. I also have another issue as seen in this picture.
Looks like a sync issue. Try a resistor on the sync line first. Around 220ohms. If not it may need a sync stripper or even to be amped.
OK, I opened up the cable and there is a resistor inside, it is soldered to pins 8 and 16.
Is that where it should be?
That is to open the rgb mode and enable auto switching if you were running it on a TV. That needs to be there. Sync is pin 20 on euro scart cables. Try the resistor on there first and see if that helps.
Thanks. Hmmm I wonder if my local radio shack is open.....
Well the resistor did improve picture a little it seems but it is still rolling and doing the tearing thing. Here is a picture after the 220ohm resistor. The first block of the color looks better, although it may be hard to tell from the pictures.
Before messing with sync strippers or amping the sync line, try and increase the resistor to around 1k ohms. If that doesn't work you'll probably have to try a sync stripper circuit or possibly amp the sync line.
I already have some 1k resistors so I'll give that a try. Should there be resistors anywhere else? Doesn't the SNES usually have three?
The 1k resistor made it completely unplayable.
Right. That isn't great then. Are you taking the sync from Composite Video or direct from the sync on the HuC6260? If it is Composite Video you'll probably need a sync stripper circuit. Remove the resistor from the scart end and build this circuit - http://gamesx.com/wiki/doku.php?id=av:lm1881 (http://gamesx.com/wiki/doku.php?id=av:lm1881) - and hopefully that should sort the problem.
The reason most RGB cables have resistors on the RGB lines is that the signal needs to be brought down to a certain level otherwise it looks too bright. Where the PCE needs to be amped, the resistors in the Scart can be omitted to.
I bought it already modded so I don't know how it was done. I'll pop it open tomorrow and take a look.
If it's using composite video as sync it could be the component box or the monitor being picky about the sync not being clean.
It is doing now on my Genesis although I don't remember it doing that in the past.
Do you have any TVs/Monitors that take RGB scart without the scart-component box?
Well I don't have any monitors that can accept scart but I did try something else. I have a SNES that I put one of Turbokon's component boards in. This is how I normally play my SNES, well I instead hooked it up with the scart cable and loaded up a Konami game and the screen started rolling. My problem must have something to do with the scart to component box.
On a side note I wished I had joined the forum prior to buying my DuoR. It's a mess in there. Doujindance put all this brown glue crap inside it.
I blame the Philips
Well, I ordered some 8 pin din connectors to make myself an RGB to component cable. The sync is now working fine, but I don't get any green. Red and blue look fine but anything green is showing as grey. I know that component doesn't actually carry green but instead uses the difference between red/blue to determine green, but I'm not sure how that plays into my issue.
Quote from: Tatsujin on 03/20/2015, 09:02 PMI blame the Philips
You don't like Philips? It hasn't been a bad tv and the picture looks pretty good on it. Of course I only paid $5 for it at a yard sale. Also, it's of the flat tube variety.
Solved my problem, although not in the way I was hoping. Oh well my Duo is looking great now an my sync issues are resolved.
Console Repair/Mod Center => Topic started by: technozombie on 03/12/2015, 05:38 PM