Sony BVM-20F1U SNES Sync Issues

[Ronin]

I just had my NES and SNES Mini modded to output RGB. I connected them to my Sony BVM-20F1U and there seems to be an issue with the sync. The odd thing is that the problem only occurs with the SNES Mini. The NES works fine. I have also been using a Sega Genesis for a while now and it works fine as well. I have played around with the monitor settings, but nothing seems to fix the problem. I took pictures with my iPad to show you what I mean.

Here is what it looks like without external sync:
http://imageshack.com/a/img921/3671/5dT547.jpg

And here is what it looks like with external sync:
http://imageshack.com/a/img921/775/PhrGoX.jpg

So does this mean the problem is with the cable I'm using for the SNES Mini? Does anyone have any suggestions?

[Guspaz]

Did you mod the SNES Mini for CSYNC? Are you using a CSYNC cable?

[Ronin]

Did you mod the SNES Mini for CSYNC? Are you using a CSYNC cable?

It was supposed to be modded for CSYNC. I guess I should double check with the guy who modded it for me. The cable is a SNES CSYNC cable I got from retro_console_accessories on ebay.

[Guspaz]

Did you make sure to terminate the outputs (the sync output particularly)? I'm not sure if it would cause your problems, but the signal levels are messed up if you don't.

[Ronin]

Did you make sure to terminate the outputs (the sync output particularly)? I'm not sure if it would cause your problems, but the signal levels are messed up if you don't.

I only see one terminate switch on the monitor. I switched it, but unfortunately nothing changed.

[bobrocks95]

If the monitor also has a set of RGB outputs, they need to be terminated as well, and that might require terminator adapters.

[korpse413]

Strange how you mentioned NES and Genesis work fine. This makes me wonder if the mod is faulty, although i'd imagine the modder would QC before shipment. But yeah terminate those outputs first I suppose, I've had shaky screen from sync with lack of my own in the past.

[Ronin]

Well, it beats the crap out of me. I put on the terminators and nothing changed. I contacted the guy who modded it and he says the cable I'm using should be the right one. So I'm sending it back to him to see if he can find out what's wrong.

[Koop]

I believe there is a different cable used between the regular SNES and the Snes Mini, the regular SNES requiring a 220uf cap or... Something like that?

I know for a fact that I can't use my NESRGB modded AV Famicom cable interchangeable with my custom SNES cable/box.

Figured I'd at least throw that out there. I'm no expert myself obviously.

Also yeah make sure you also got terminators on the output, at least that is what I was told by more educated people!

[Finger]

Had the same issue with same hardware (snes mini rgb and bvm) when I was using a pure sync rgb cable. Switched to a composite video as sync rgb cable and my issue was solved.

[Guspaz]

Maybe the monitor doesn't support csync? In that case, you'd be better off with luma sync... which also requires a mod on the SNES Mini, since the luma and chroma pins aren't connected either.

The original SNES and a correctly modded SNES Mini use the same cables.

OP, is it an NTSC, or a PAL SNES? There's a huge difference in sync voltage between the two.

[Finger]

It does support csync. Had the issue only with snes. Affirm if your console support luma, it works petfectly too.

[atheistgod1999]

I have a BVM-20F1U as well and it handles both composite-video-as-sync and csync just fine with my Genesis (I had an RGB cable with sync on the former, but I opened up the DIN and desoldered that wire from that pin and soldered it to the csync pin so now it's csync).