Master System RGB not working

[unehed]

Hi,

I'm new to this forum. Have been lurking a lot in the framemeister thread.
I just received euro scart cable with csync from retrogamingcables.co.uk. Actually two. One for Mega Drive 2 and one for Master System.
The Mega Drive works fine and it works both if I plug the cable straight to my tv or into the framemeister. The Master System however does not.

It sort of works for a second or two. I can see the Sega logo in red and then it just fades to black. If i pull the cable almost all the way out and then position it in a precise position i get picture. Like I can get a completely green picture actually showing the game if I hold the cable steady in that position.

I'm not very good with electronics but my thinking is that there might be a capacitor somewhere discharging? I've opened up the Master System and looked around but I can't find anything obvious.

The Master System works on RF although the picture is REALLY noisy. Even by RF standards I think.

If it has something to do with a capacitor do you guys have any idea which one it could be? Any ideas are welcome since I'm a little lost with this right now.

[TheBearded1]

I don't know the answer here, but it'll help folks if you include details about any upscalers, tv's, capture cards etc. Basically: what are you connecting this thing to?

[unehed]

I don't know the answer here, but it'll help folks if you include details about any upscalers, tv's, capture cards etc. Basically: what are you connecting this thing to?

Yeah so as I wrote in my first post I've tried connecting it directly to my tv and to my Framemeister (xrgb mini). The tv is a Sony LCD. I'm not sure what model it is and I'm not home so I can't check right now.

[RGB0b]

I may be able to help. Does your RGB cable use composite video for sync, or csync?

Edit: I'm sorry, I'm still half asleep and skipped right past the part where you said you're using csync. Do you have a multimeter? Also, what revision of the SMS do you have? On the bottom, it'll say "Model No: 3010" or something like that.

[unehed]

I may be able to help. Does your RGB cable use composite video for sync, or csync?

Edit: I'm sorry, I'm still half asleep and skipped right past the part where you said you're using csync. Do you have a multimeter? Also, what revision of the SMS do you have? On the bottom, it'll say "Model No: 3010" or something like that.

I'm at work right now but I'll get back to you with model number tonight. It is a PAL console, the first version of the Master system.
I don't have a multimeter but it seems like a useful tool to have so I might buy one after work. Will I be ok with the cheapest shit multimeter or should I go for something better?

[RGB0b]

All you'll need it for is to trace pins, so the cheapest one will work fine.

[Guspaz]

Don't go too cheap: I had a multimeter that didn't do continuity checking, and tracing stuff was a real pain. Replaced it with an auto-ranging one with a continuity check (it was on sale for the same price I paid for the first one) and it's much easier.

[unehed]

Don't go too cheap: I had a multimeter that didn't do continuity checking, and tracing stuff was a real pain. Replaced it with an auto-ranging one with a continuity check (it was on sale for the same price I paid for the first one) and it's much easier.

I'm looking at this one.
http://images.biltema.com/PAXToImageSer ... 3_xl_2.jpg

It's cheap but it looks like it has continuity testing? The symbol that looks like a wifi-symbol is continuity testing right?

[unehed]

Actually I think I'll go with the Uni-T UT33A multimeter. That's got autorange. I'll buy one of those tomorrow.

The revision my master system: 3005-18-A.

Here's an image of the board:

[RGB0b]

I'm having a similar issue with a Japanese MK-2000 SMS. If I use the mulit-out, I get either no image, or a distorted image. If I connect RGBs directly to the CXA1145, it works perfectly: http://console5.com/wiki/CXA1145

Is this something you could try as well? Also, I'd double check the connections between the CXA1145 and the multi-out. Most SMS' I've seen are connected directly, but the Japanese SMS systems have components between the CXA and the multi-out.

[RGB32E]

Try using pin 11 for sync. (pin 11 > 220uF or 470uF > 75 ohm > out). I think you would have better results with the CDi RGB mod had you done this!

[RGB0b]

Try using pin 11 for sync. (pin 11 > 220uF or 470uF > 75 ohm > out). I think you would have better results with the CDi RGB mod had you done this!

Yeah, sorry unehed, I should have specified that: Pin 11, or if that doesn't work try luma (pin 16). Thanks for the reminder RGB32E.


For the CDi mod, I actually tried adding a resistor and capacitor and it worked perfect on my RGB monitors, but not through my capture card. I figured since I'd only tested two CDi's, I'd add the into about a sync stripper to be safe. You wouldn't happen to know any info about the Bt9106KPJ chip in the top-loaders though, would you? At the moment, there's only an S-Video mod for those. Maybe PM me if you do...I don't want to get off topic here