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 Post subject: mega drive black and white
PostPosted: Wed May 15, 2019 6:03 am 



Joined: 14 May 2019
Posts: 9
dont know if i can ask this here ,but i have a pal megadrive that only playes in black and white no mods where dont to it
but i have a svideo box so far i tried panasonic plasma tv difrent settings ntsc pal secam auto etc all black and white picture is clear
all games are pal ! and i also tried a commodore monitor 1701/02 via chroma luma -svideo same thing picture is crystal clear but black and white
i orderd a svideo switch i saw a post here maybe it wil work for me
iam using this adapter
i dont know how to post pics of the internal componants
but see link https://item.taobao.com/item.htm?id=549 ... .N.35c5da2

https://www.youtube.com/watch?v=5GfcmhfbJxg&t=89s

update : i bought this selector works perfect but stil no color after changing consoles when they are on
i have color on n64 snes but not megadrive
https://www.ebay.com/itm/Audio-Visual-S ... 1251017163

i posted pics on this forum of the internal components https://gbatemp.net/threads/mega-drive- ... te.538505/


Last edited by scroeffie on Wed May 15, 2019 1:18 pm, edited 1 time in total.

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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 11:50 am 



Joined: 06 Mar 2017
Posts: 101
It's probably an issue with the colorburst frequency. I'm just assuming here as I don't know anything about the S-video converter you are using, but I think it only properly works for NTSC systems and not PAL systems (I see only 1 crystal oscillator in the device). If you send a PAL signal with NTSC colorburst frequency, the mismatch will cause the image to come out black and white.


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 1:21 pm 



Joined: 14 May 2019
Posts: 9
Makinx wrote:
It's probably an issue with the colorburst frequency. I'm just assuming here as I don't know anything about the S-video converter you are using, but I think it only properly works for NTSC systems and not PAL systems (I see only 1 crystal oscillator in the device). If you send a PAL signal with NTSC colorburst frequency, the mismatch will cause the image to come out black and white.



so i need to change it to a Crystal Oscillator 4.433MHz PAL


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 1:36 pm 



Joined: 06 Mar 2017
Posts: 101
Yes, taking a closer look at your pictures, I see that the crystal is 3.79545Mhz, which is the NTSC frequency. Changing that to a PAL frequency crystal should work. The crystals are readily available online and are very cheap.


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 2:51 pm 



Joined: 14 May 2019
Posts: 9
man this makes so much sense now duhh ,and this adapter is from japan is a japan megadrive ntsc ?
i wil order one and change it asap thanks
i wil update if it works
if someone wants to order this adapter you need to do it via superbuy very easy !


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 3:28 pm 



Joined: 06 Mar 2017
Posts: 101
The Japanese Mega Drive is indeed 60hz NTSC, same as the Genesis in the USA/Canada.

The European and Australian Mega Drive are 50hz PAL. Your converter box was apparently not designed with those consoles in mind.

I hope replacing the crystal works! Keep us posted.


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 4:37 pm 



Joined: 14 May 2019
Posts: 9
yes i wil tel you if it works or not


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 5:46 pm 



Joined: 13 Apr 2013
Posts: 253
It would be better to use an RGB Scart cable instead of changing the xtal. It will give full color without any issues.


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 Post subject: Re: mega drive black and white
PostPosted: Wed May 15, 2019 6:03 pm 


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Joined: 31 Jul 2017
Posts: 160
The commodore monitor he's using for chroma/luma doesn't have a scart input, but what I find odd is the 1702/01 monitors are supposed to support both NTSC and PAL interchangeably.

That's a neat rgb to s-vid conversion box, anyway.


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 Post subject: Re: mega drive black and white
PostPosted: Thu May 16, 2019 6:57 am 



Joined: 14 May 2019
Posts: 9
true scart rgb is better but i dont want to i have 2 commodore monitors 1 for my c64 of course and the other for snes nes n64 and megadrive


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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 8:54 am 



Joined: 14 May 2019
Posts: 9
oke i changed the crystal but the crystal has a difrent shqpe does that matter
it says 4.433619 ,but the image is crystal clear but stil black and white
all my games are pal sound is working perfect

bought this one https://www.ebay.nl/itm/Quartz-Crystal- ... 3804529046


Last edited by scroeffie on Fri May 24, 2019 1:28 pm, edited 1 time in total.

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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 11:39 am 


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Joined: 09 Aug 2017
Posts: 1278
Location: Australia
how did you fit a 2 leg crystal to a crystal oscillator 3 leg slot?


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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 12:56 pm 



Joined: 14 May 2019
Posts: 9
the slot is not 3 legs you mean the pcb has 2 holes for the crystal not 3


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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 1:54 pm 


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Joined: 04 Aug 2007
Posts: 494
Location: Europe
In addition to the 4.433MHz you should change the MB3516A mode to "PAL" - lift the leg #7 of the encoder so that it doesn't touch the pad (+5V), and connect the leg to ground.
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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 3:00 pm 



Joined: 14 May 2019
Posts: 9
RGB wrote:
In addition to the 4.433MHz you should change the MB3516A mode to "PAL" - lift the leg #7 of the encoder so that it doesn't touch the pad (+5V), and connect the leg to ground.



so leg 7 is that from above the chip how do i know wich one is leg 7
some of these legs are not solderd !!

http://pdf.datasheetcatalog.com/datashe ... Xrxtqy.pdf

found the datasheed oke wil try after dinner ,so desolder leg 7 and connect it to ground


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 Post subject: Re: mega drive black and white
PostPosted: Fri May 24, 2019 4:11 pm 



Joined: 14 May 2019
Posts: 9
YESSSSSSSSSSSSSSSSSSSSSSSSSSS ITS WORKING I HAVE COLOR ITS OVER 9000 :mrgreen: :D :D :lol: :lol:


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