Genesis 2 + arcade monitor

[BMF54123]

I took the caps and resistors off, and the brightness is perfectly stable now, though I have to turn the monitor's black level all the way down and the contrast all the way up in order to get a decent picture. Is this just a result of the difference in voltage levels between arcade boards and a Genesis? (As long as this doesn't damage anything in the long run, I don't mind having to make the adjustments.)

Also, now that I've hooked up the ground line, I'm having some audio issues--a different issue with each of my two Model 2s (they're different hardware revisions; I can provide more info and pics if you like). With the older one (rev. 0), there's a lot of clipping and fuzziness during loud music and sound clips; with the newer one (rev. 2.3), there's no clipping, but the PSG channels are barely audible when FM channels are playing. Is there an easy way to fix this?

[phreak97]

plug the audio into an external amp and speakers? sorry, im not gone be very helpful with this one:P

[viletim]

BMF54123,
That's the effect of the DC voltage on the video signals. It's normal and won't hurt anything (though it seems your monitor doesn't have a video clamp in there after, that service manual is a bit misleading). If it bothers you then you might be able to make it go away by putting a diode in series with each colour signal. Cathode (sripe) towards the monitor. Any small signal diode like the 1n4148 or 1n914 will do.

As for the audio...i've got no idea...what are you using for the amp? and does it only distort when the monitor's connected? what if it's not turned on?

[BMF54123]

Whoa...I guess that's how they're "supposed" to sound. I connected both to my TV via an ordinary AV cable, and sure enough, the problems were still there (track 11 of Rocket Knight Adventures sounds horrible on the rev. 0). The main difference between the two consoles is that the rev. 2.3 has separate chips for everything (it has a genuine Zilog Z80, YM2612, Motorola 68K, etc.), while the rev. 0 has everything integrated into a couple less chips. It seems odd that the later revision would have separate chips, but perhaps it was cheaper than manufacturing custom ones.

As for the amp, I'm just using a powered Labtec speaker/subwoofer set.

[RGB32E]

So... the main problem was the wiring... like I suggested looking at!  I hope you enjoy your Genesis on an RGB monitor!

[Guest]

Sorry to butt in here but I have a question. I have a Genesis that I'd really like too hook up to my TV with a SCART RGB-cable. I have one for my Mega Drive but when using it on my Genesis the colours gets way to strong. Even If I set it to the lowest setting possible for my TV they are still too strong. I figuerd this thread sort of handles this problem but mine's not quite the same as BMF54123's.

I'm not that good at this stuff so I'd like som help. I was thinking that all I needed to do was to make the signals weaker? And how would I go about doing that?

[viletim!]

Guest,
Maybe it would have been better to start a net thread, this one's long enough as it is.

Are you saying that the cable works perfectly on the Mega Drive but not on the Genesis? Did you buy it or is it a home-made job?

[Guest]

Yeah, it works perfectly on the Mega Drive but on the Genesis the colours get's way to strong. Light blue and white both become white. And I bought it, it's made by a company called Fire.

Oh and you had to register to make a new topic

[viletim!]

I thought the video output from the Mega Drive and Genesis was identical... maybe it's not. Can you remove the shell from the SCART end of the cable and check to see if there are any electronic components inside?

[Guest]

There's one resistor in there, and also one cable that's loose.. I could mark where the resistor is and where the left-over cable is going. The SCART connector only has the number of teeth, or whatever they are called, that is needed so I could check wich one it's supposed to go to. But I don't really have the time right now. I'll do it someday later

[vileitm!]

There's one resistor in there, and also one cable that's loose..

That doesn't sound too good but I don't think it can cause the problem you describe. I think you'll need to put a few components in series with the video wires as depicted here.

It's interesting that your Mega Drive does work with the cable though... I've never seen one that didn't require the caps/resistors in the cable. What model is it and where did it come from?

[Guest]

First of all it seems like the left-over cable have nothing to go to so I figure maybe it's ground that's supposed to go to the metal part around it, It doesn't seem to be grounded now. According to that picture it looks like it's supposed to go to 4, 5, 9, 13, 17, 18 and then the shell around it. The only ones of those that are connected are 17 and 18, with each other.

Everything else is like on the picture, except for the ground then, and there is nothing on the colours no resistors or capacitors or anything. And I think the resistor between 8 and 16 is of 150 ohm not 180.

The Mega Drive is a normal PAL model 2. Got it 93/94 or something.