x eye scart to yuv sync problem

[mvsfan]

i figured id research a lot before i decided to get into scart.

i replaced my 21 year old tv with a sony kv-32fs120 crt with component.

got a scart to yuv converter and an Rgb wired scart cable.

I get a nice, sharp, clear x eye bios screen when i turn it on. Works great. For about 2 seconds.  then the colors start to fade to green, then black till the picture is gone, and thats it.

It doesnt do this when hooked up through composite.

I believe that the sync is being dropped.

ive done a lot of work hooking things up to arcade monitors and never had this problem.

unfortunately though i dont have a cable for an snes to test out if its the console, and i dont have another sega console.

the x eye is it. picked it up about 10 years ago for 25 bucks.

any help would be appreciated. thanks.

[kendrick]

You happen to know which variety of video encoder is in that particular X'eye? Some of the later models used a CXA-1145 drop-in replacement that doesn't have quite the same sync output. If you're not willing to open the unit, it's probably worth heading down to your local indy game shop and grabbing a Genesis 1 unit just for test purposes.

[mvsfan]

mabeye i found the problem. I was checking the wiki and came across a sync seperator circuit. mabeye this is what i need.

also, the video encoder is a sony cxd2500bq

[ApolloBoy]

also, the video encoder is a sony cxd2500bq

I think you're looking at the wrong thing, the CXD2500BQ is a DSP for audio. Look towards the rear of the board for a small chip, it should be located somewhere behind the power jack.

[mvsfan]

yeah, i was looking at the wrong thing. that IS a small chip. its actually a cxa1145m. i found the datasheet just to be sure it is the RGB encoder.

[mvsfan]

i found my own solution to this, sort of. I came across a guy who had to mod his wondermega because it wasnt outputting good sync. he attached a wire for sync to the svideo connectors luminance.

But.. the x eye doesnt have a s-video port so i basically did the same thing but i took the sync off of the luminance directly from the encoder.

i also cut the trace going to the sync pin on the multi out, and soldered a wire from pin 16 of the cxa1145m to the now cut sync line on the multi out.

Works like a charm except for 1 thing.

It drops sync for a second when their is a big bright flash (think contra hard corps.) not really an issue but its annoying.

[mvsfan]

When i was searching for this info, couldnt find it on gameSx.

This http://www.assemblergames.com/forums/showthread.php?t=29294 talks about the mod for the wondermega, and is actually linking back to an image on gamesx.

if it helps anyone else who is looking for it, Great.

since i last posted, the x eye has been working perfect, though some genesis games are um, real ugly on RGB.

id reccomend anyone who just hooks it up to try Sonic, or Alien soldier first.

ive also since ordered a cable for my snes.

[mvsfan]

to the people who replied, thanks for your help.

its still working great.

ive been leaving this topic alone for a while because i was hoping i could find an answer on my own about why its dropping the picture on very bright white screens.

the only game ive noticed thats really bad is Contra Hard corps.

any ideas?