Keene SCART Commander with NESRGB problem...

[Josh128]

Recently purchased a Keene SCART commander from the trading post in this forum. Seems like a nice piece of hardware, received in good condition w/ original box, etc. Seemed to perform well save for a minor issue that it wont auto-switch to my Genesis (have to push the switch button to get it), but I noticed an issue a couple days ago that concerns me when using with a NESRGB modded NES front loader NTSC console.

While the picture appears perfect at first glance, if you watch it closely, especially on still graphics, there is a very slight, digital-looking horizontal wobble in the picture. It seems to happen about every couple of seconds. The best way to describe it is to say its a very slight (one TV pixel or so) horizontal shift/wobble on the top third of the screen, then the middle third, then the bottom third, seemingly in that order, over a period of about a half second. It repeats this process every second or two. It almost appears to be some sort of a sync-type issue.

At first I thought it was related to my NESRGB, as none of the other systems (SNES, Genesis, DC) exhibit this behaviour with the Keene, but this morning I decided to bypass the Keene and go directly to my SCART>Component converter and the issue completely disappears when bypassing the Keene. I tried several times to make sure it wasnt a loose connection or so, but I get the same result each and every time.

First thing I tried was to move to a different input port on the Keene, the problem followed, no matter where I plug in the NESRGB. It seems to be related to the active circuitry of the Keene. Im using the SCART cable with the small round plug on the NES side that Tim provides with the NESRGB kit.

Can anyone here with a Keene and a NESRGB test this for me? Im absolutely certain this ONLY occurs with the NES, the other systems are perfect. This is pretty disheartening, as I paid a pretty penny for the Keene.

Wonder if perhaps the levels of the R,G,B, or S signals of the NESRGB differ from those other systems and are perhaps causing the Keene to try to re-sync or re-switch to the signal or something like that. Im using C-Sync on all my systems as far as I know (not certain about the DC, no modding was done, just an Ebay SCART cable for it).

At the very least if anyone could test their setup, and look very closely on still graphics and see if they see the same issue, would be greatly appreciated.

[Josh128]

Anybody out there with a Keene switch and an NESRGB?

[Blaasvis]

I have a somewhat similar issue with my scart box not keene. When i disconnect all other scart's it is fine.
Can you test this as well ?
Also Can you take a picture of the problem i might help

[Josh128]

Thanks for replying. Unfortunately I could take a picture but you wont see the problem-- I'd have do a video, zoomed in for you to see. I may do that when I have chance. Its a very subtle, but very annoying problem.

Ill try to unplug all the other SCARTs from the switch as you suggested, but I think it must be related to the active switching/amping circuitry in the Keene. The problem is too consistent like clockwork, and almost digital-looking.

Its only with the NESRGB, the other systems are fine.

[airs]

Is your NESRGB using composite video for sync? I believe the NESRGB provides composite video, luma, and csync so you could rewire it to use csync and see if that helps.

[Josh128]

Is your NESRGB using composite video for sync? I believe the NESRGB provides composite video, luma, and csync so you could rewire it to use csync and see if that helps.

Yes, I have it wired for C Sync. I originally wired it sync on composite video and had jailbars, even direct to the TV. Switching to CSync gave a perfect picture. I hate to open it back up, as its perfect unless I use the Keene.

I was thinking to maybe try Sync on Y/Luma, but thats a long shot, I was really hoping somebody out there with a Keene and a NESRGB would check theirs for me and reply.

Last night I unplugged everything else out of the Keene except for NESRGB, problem is still there.

[airs]

That's a bummer. I was under the impression that the Keene was one of the best switches.

Are you planning to add more systems to your setup in the future? If so, maybe you could get a different switch (superg's gscartsw perhaps) and use them together. Consoles that work with the Keene could be plugged into it, and the NES (and future consoles) could be plugged into the gscartsw. The Keene's output would also be plugged into the gscartsw, then the gscartsw into your display.

[Josh128]

That's a bummer. I was under the impression that the Keene was one of the best switches.

Are you planning to add more systems to your setup in the future? If so, maybe you could get a different switch (superg's gscartsw perhaps) and use them together. Consoles that work with the Keene could be plugged into it, and the NES (and future consoles) could be plugged into the gscartsw. The Keene's output would also be plugged into the gscartsw, then the gscartsw into your display.

I actually considered a second switch, maybe the cheap mechanical one that has decent reviews, to do just what your saying. Problem is, my chest entertainment center is pretty crowded already, and the 4 ports on the Keene are EXACTLY what I need for all my systems once I get my AA VGA to Component converter in for my DC, and I dont see the need for additional ones in the future. So, the best solution would be to try and get a setup that the Keene works with.

I may try to pop open my NES tonight and move the sync wire to Y and see if that fixes the issue. Ill post results, of course.

[airs]

Understood. Btw, how are you planning to handle 240p titles on the DC with the VGA to component converter?

[Josh128]

Understood. Btw, how are you planning to handle 240p titles on the DC with the VGA to component converter?

Thats a good question-- dont most of them support VGA mode? I have SF3 Double Impact, Im fine running it in 480p, that is, unless its not compatible.

BTW, heres the video of my problem-- note the text jerkiness at :37 and later.

https://www.youtube.com/watch?v=TIbSSHk ... e=youtu.be

VileTim responded on the NESRGB thread that I might have luck trying PPUV for sync. At this point I have no other options but to try. If it doesnt work, next step is to mod my CSY-2100 clone for RCA Audio out, because I just realized that without the Commander I have no way to get audio to the TV if I plug the NESRGB SCART straight into the CSY. I have an EXTREMELY CRAPPY breakout box I was using before I got the Keene, I refuse to use it anymore as its so shoddy if you just touch it the colors will get all distorted on the screen. I had gotten used to it before, but the Keene eliminated the need for it and showed me how crappy it really was.

[Josh128]

Quick update on this issue:

Per Tims suggestion I used PPUV on the NESRGB for sync and after going back to CS# after an initial failed attempt to get it to work (still have no idea why it didnt give a picture), I moved the wire back to PPUV and got a picture.

Long story short, it didnt completely fix the problem, but reduced the visibility/amplitude of the horizontal pixel shifting to the point where its no longer visible at normal playing distance (for me, about 4.5ft). Its good enough that I can leave it on the Keene. If you look very closely at the top and bottom of the screen, you can still see some shifting, buts its no longer so easy to see. Again, if I dont go through the Keene, its 100% perfect. Something in the Keene doesnt like something in the sync signal of the NES and/or NESRGB.

As for the Audio Authority VGA to Component transcoder, tried it this afternoon, its DOA. Im pretty cheesed about it and have requested a refund from the Ebay seller.

[Josh128]

Quick update on this issue: As reported earlier, using PPUV on the NESRGB greatly reduced the pixel "shifting" effect through the Keene.

Interestingly enough, I was playing around this evening with my (newly repaired) Genesis 2 on my F4500, wanted to see if it looked any different than the Genesis 1 when using RGBs, when I noticed 2 things:

First-- while the Keene refuses to auto-switch with the Genesis 1 and Retro Console Accessories raw boosted sync cable, it readily switches with the Genesis 2 and its raw sync cable from Retro Console Accessories with one caveat--

The same random "pixel shifting" seen with the NESRGB using C-Sync through the Keene shows up here, and its identical. Very strange, but it must have something to do with the strength or amplitude of the C-Sync signal I guess. Funny thing is it does not occur with the Genesis 1, and cable I use for it also claims to be boosted sync, but it must be at a lower level because as mentioned earlier, the Keene can not auto sense/switch to it.

Other than the pixel shifting with the Keene, the Genesis 2 output looks as fantastic on my plasma as the Genesis 1-- no discernable difference. Even after experiencing them on the Trinitron Wega, the 240p mode on my F4500 still continues to impress me-- it just looks very colorful, with a very subtle and natural softness that looks more pleasing to me than Ive seen 240p look on other HDTVs. Im still a huge fanboy of the set.


Again, if I take the Keene out of the equation the pixel shift completely disappears. Oh well, just trying to further the knowledge of this issue.

[noonan2678]

I have Keene switches also (currently not in use) and an NESRGB on the way in a couple of weeks. I'll def chime in with some testing results once I get the system in.

[Josh128]

I have Keene switches also (currently not in use) and an NESRGB on the way in a couple of weeks. I'll def chime in with some testing results once I get the system in.

Cool, would like to hear about it. Dont know if its the Keene+Samsung combo or what, but when I take the Keene out and just go to the TV, its perfect. Only using a different sync on NESRGB (PPUV) eliminated the problem (mostly) with the Keene.

[deltronik]

I've got a NESRGB and scart commander. I've currently got the NESRGB hooked straight into my Extron Crosspoint and haven't used it through the Keene. Now that I think about it, the hidef genesis is going straight to the Exron too... SNES, N64, PS1 are going into the Keene and then sync strike, then the Extron.

I'll play around and see if I notice the Keene doing anything funny to the sync, although I am having a hard time visualizing what you are describing... I'll be a bit bothered if I do notice something now...

[Josh128]

I've got a NESRGB and scart commander. I've currently got the NESRGB hooked straight into my Extron Crosspoint and haven't used it through the Keene. Now that I think about it, the hidef genesis is going straight to the Exron too... SNES, N64, PS1 are going into the Keene and then sync strike, then the Extron.

I'll play around and see if I notice the Keene doing anything funny to the sync, although I am having a hard time visualizing what you are describing... I'll be a bit bothered if I do notice something now...

I posted a youtube video of the issue either in this thread or the NESRGB one.

Its in post #10 of this thread.

[deltronik]

I posted a youtube video of the issue either in this thread or the NESRGB one.

Its in post #10 of this thread.

Ha, I must have skimmed right past that. I'm home from work today awaiting my OSSC delivery, so I'll take a close look and let you know if I see anything similar with my setup.

[deltronik]

OK, just tested and I do not see any pixel shifting on my Twin Famicom NESRGB through the Keene switch.

My chain was NESRGB (csync) >> Keene Scart Commander >> Sync Strike >> Extron RGB >> GBS-8220 (CFW Project) >> Gefen VGA-DVI >> Panasonic p50s60

AND

NESRGB (csync) >> Keene Scart Commander >> Sync Strike >> Extron RGB >> EBAY SCART-YUV >> Panasonic p50s60 (detects 480i so of course there is motion artifacting)

I still need to test Genesis 1 and do some back to back comparisons.

//edit: I don't usually have these hooked up to the Keene/sync strike combo because they play nice with the Extron already being csync.

Left sync strike out of chain...

[deltronik]

Back to back testing of the NESRGB through the Keene + sync strike + Extron vs just the Extron showed no discernible differences to my eyes.

My Genesis, on the other hand, does not play nice at all with the Keene. I've always had trouble with the keene auto switching + Genesis, but when I just tried it, I could not get my Genesis to display at all, even manually switching.

Hooked my genesis back into the Extron and it works fine!. I'm at a loss

[Josh128]

My original model Genesis does not auto-switch through the Keene either.

[Josh128]

Old thread, but been troubleshooting the problem on this SCART Commander and today I isolated the problem to the Green output of the 2450CS video amp. Turns out it has nothing to do with the NESRGB at all. I removed the IC and jumped the inputs to the outputs and got a perfect picture, just dim. Being that the green no longer "jitters", Im hopeful that there is nothing in the input that is being amplified and causing the problem, rather that its just the IC itself. Apparently this Keene had this issue since I first bought it some 5+ years ago at the trading post on this forum. Its just the problem was so subtle that I didnt realize it occured regardless of what system or port was being used. It was always present on the output.

Ordered a replacement 2450CS and intend to solder it in place and fix this problem once and for all very soon!

[Josh128]

After all these years I found a fix to this issue!! Again, problem turned out to be with the SCART Commander and not the NESRGB. Problem would manifest itself on CRT and plasma when going through a CSY clone RGB>YUV converter. Also tried the VGA out of the SCART Commander to an AA 9A60. Same issue. Also noticed that issue would manifest with only an output plugged into the converter and NO INPUTS connected. I verified this by looking at the green "Video" that is displayed by the OSD on my Trinitron. Oddly enough, when the SC was plugged in, the rhythmic horizontal pulsing that goes from right to left, top to bottom of screen would cause a couple lines of the "Video" OSD indication to warp periodically.

Tried numerous things to solve this issue. Contacted Keene and was told that the SCART Commander was designed by an outside firm for Keene that had since gone out of business, and that Keene could not find a schematic for it, odd as that is. During all this, I was able to track down the issue to the "Green" output of the EL2450CS video amp on the output of the SC. They recommended a generic "re-cap" of the electrolytics, so I did just that. Recapped the entire output section of the SC, no difference.



So, switching gears, I attempted to scope the signal coming out of the amp when the issue was visible. Did it with no inputs on the SC and did see some strange pulsing on the output of the amp, even with nothing connected to the input SCARTs. Could not see anything bad on the input to the amp though. After unsoldering the amp and its breakout PCB, I jumped the input RGB and S signals directly to their respective output pins. I got a nice, dim picture, but whadaya know? No more visible problem. Tried all kinds of different content, the issue was not present. So, I figured it must be the video amp right!? WRONG. I got a rude awakening after ordering and replacing the 2450 video amp. Same exact issue.





Next I decided to check the 4 MHz crystal, because I noticed while attempting to scope certain pins on the PIC, the problem would clear for just a couple seconds, then the screen would turn black until I removed the probe. Turns out that was the input to the PIC from the crystal. Oddly enough, when I interrupted the oscillation of the crystal by touching or probing one of its leads, the problem would immediately cease , but then I would lose the picture completely as the PIC lost its timing signal. I did notice though, that the screen was not "frozen" for those couple seconds when I touched the crystal, but it was still live / displayed animation.



Well, checking the crystal showed a near perfect 4.0002 MHz, so another dead end, but seeing the problem cease when the PIC lost timing gave me the idea to connect a 470 ohm resistor to ground and touch the ungrounded side to various points on the board to see if I could make the problem better or worse. When I got to the dual 4x1 signal multiplexer I finally discovered that touching the output leg that switches to each of the 4 "VDET/Blanking" (SCART Pin 16) inputs made the problem disappear, and even better this time, caused no other issues to the SC operation.



So after scoping and checking with a DVM, I discovered that the output on that multiplexer always had a ~2.5Vdc voltage on it, even with no inputs connected, and when I would put the resistor in parallel to ground it would drop the voltage to about 400mv. I checked on the Video Detect function of SCART and found that its used to signal the display device whether to use RGBS or composite video. RGBS is actually supposed to have 1-3V and composite is supposed to have 0-400mv. So what I actually did was manually set the voltage to the composite video level. I have no idea why that fixed the problem, my theory is that having the RGB blanking level present was causing something on the SC to continually check or poll for signal changes when there was no need to. Maybe the small IC that is fed the blanking voltage has an issue, I dont know. As a test I also lifted a component off the trace coming from the VDET output to break the circuit, and it functions the same as having the resistor in parallel to ground, presumably because the working range for comp.video is 0-.4V.



Regardless, everything on the Keene Scart Commander is now working flawlessly, some 5 years after I purchased from the hardware swap forum here. I've been through a ton of real life stuff since aquiring it, and its very satisfying finally putting the problem to bed and being able to use it.