Faroudja LD100 jumping picture

[Bostich]

I recently acquired a Faroudja LD100 and I'm having some issues with the RGB output.  I ran the RGB output of the LD100 into my Keene RGB2C component video transcoder which was then connected to my TV (Sony KV36HS510).  I am getting a jumping picture when connecting older game systems to the LD100.  The picture isn't jumping around chaotically--it's very consistent.  Roughly twice a second the picture jumps upward a few lines then comes back down.

For the sake of consistency, I used the composite video cable for each system for these tests.  The following systems produced a stable picture from the RGB output of the LD100:  N64, Saturn, Playstation, Dreamcast, GameCube, PS2, and Xbox.

These systems produced a jumping picture from the RGB output of the LD100: NES, SNES, Master System, Genesis, and Jaguar.

For each of these tests, I also had the VGA output of the LD100 connected to my computer monitor (ViewSonic VA903b) and noticed it had a stable picture in all cases.

I also tested the SNES and N64 using the S-video cable and got the same results.

I'm not sure if there is actually a problem with the RGB output of the LD100 or if it just isn't playing nice with my Keene transcoder.  One thing I noticed from looking at the specs is that the LD100 produces a sync signal with a 4V peak.  The Keene transcoder says it is expecting a 1V peak.  With that in mind, I thought perhaps the LD100 was overloading the sync input of the Keene transcoder under certain conditions.  I don't know why it would differ from one system to the next, but again the VGA output from the LD100 was fine for all systems.

So I tried putting various resistors inline with the sync signal to see if it made a difference.  Basically I found that values of 1500 Ohms or less still gave me the jumping picture.  Values of about 2300 Ohms and above gave me no picture at all.  I don't know if there is a sweet spot somewhere in there between 1500 and 2300 Ohms or if I was even on the right track, so I stopped there.

Does anyone have any ideas?  I'm not sure what else to try at this point.  The only other thing I know of is to just get a VGA to component transcoder and use that to hook up the LD100 to my TV.  I'd rather find a way to get the LD100's RGB output to work if possible since that would be one less converter to buy.

[RGB32E]

Does your LD100 have a sync switch (next to the VGA connector)?  Not all have that, but you might try changing it if you have that option (mine does).  Also, from your application, it looks like all you really need is a RGB to component converter (and let your Sony TV do the rest).  

[Bostich]

Yeah, it has a switch that can be set to "auto film" or "video".  I tried both settings and it didn't make any difference.

You are right that I don't necessarily need the LD100 to utilize the RGB outputs of my game systems.  The reason I decided to give the LD100 a try is because I had read it was a really good line doubler and was good at eliminating comb artifacts, etc.  The comb artifacts are especially noticeable on my TV with systems outputting a "240p" resolution.  (i.e., most of the systems that have a jumpy picture going through the LD100)  My TV doesn't simply display the "240p" signal with scanlines and all--it tries to fill in the scanlines with colors and creates comb artifacts in the process.  I kind of like not having the scanlines, but I had noticed that my TV didn't quite do it "right".  Even with the jumpy picture, I could tell the LD100 does a much better job eliminating the comb artifacts than my TV does.  So basically, I just saw the LD100 as the next step towards getting the ultimate picture quality out of my game systems.