EverDrive Forum

General => Off Topic => Topic started by: JBJBJB on July 26, 2017, 05:10 AM

Title: NTSC sync problems?
Post by: JBJBJB on July 26, 2017, 05:10 AM
Hello, i have a PAL Mega Drive 2 with a Mega EverDrive X7 that i recently 50/60 hz modded, works fine on one of my TVs, but on my main Samsung TV the picture (in NTSC mode) randomly goes black for a few seconds (but looks perfect while it works)
As i live in Sweden this is mainy a PAL TV, but the manual sais:
"Colour/Video System: Analogue: PAL, SECAM, NTSC-4.43, NTSC-3.58, PAL60"

So NTSC should work right?

The RGB cable i have is connected like this one:
(http://members.optusnet.com.au/eviltim/gamescart/mega2.png)

Most ground pins (like pin 18) aint connected to anything on the scart side.

Could my Samsung TV be extra picky and requires the Sync (pin 5 on the Mega Drive 2 end) to be connected?

I am using a scart switch with the option to switch between RGB and composhit, and i get the same sync problems in both RGB and composhit mode. (but just with NTSC, works perfect with PAL)
I also tried to connect the Mega Drive directly to the TV without the switch, but that made no difference.
Title: Re: NTSC sync problems?
Post by: ozzy2k on July 26, 2017, 11:12 AM
Mostly all modern televisions need CSYNC. So give it a try with Pin 5.
Title: Re: NTSC sync problems?
Post by: RetroRGB on July 26, 2017, 04:46 PM
Also, when using csync instead of cvbs, make sure there's a 470 ohm resistor, then a 220uF cap on the csync line of the SCART cable.  Also, make sure to test by plugging it directly into the TV: http://www.retrorgb.com/csync.html
Title: Re: NTSC sync problems?
Post by: JBJBJB on July 26, 2017, 10:56 PM
Hmmm guess i'll have to build a new cable then, there seems to be no way to get into the Mega Drive 2 connector on this cable =/
Title: Re: NTSC sync problems?
Post by: densy on August 04, 2017, 10:58 AM
A 50/60 modded PAL Mega Drive will not produce a perfect 60hz signal in my experience. Could be that your TV has a problem taking this slightly off spec signal. My modded PAL Mega Drive works fine when connected to the Framemeister but it does take some tweaking to get it to display smoothly without some occasional visual stutter.
Title: Re: NTSC sync problems?
Post by: FeverDrive on August 04, 2017, 10:53 PM
If everything else fails the cheaper solution is just to buy a US MegaDrive (Genesis ;))
Title: Re: NTSC sync problems?
Post by: JBJBJB on August 17, 2017, 06:05 PM
Does your RGB-cables have C-Sync pin connected, or does it look like mine? (see picture in first post)

A real US Genesis might be a sulotion, but it would be nice to be able to have both in the same console.
Title: Re: NTSC sync problems?
Post by: JBJBJB on September 29, 2017, 02:54 PM
I found no schematics for a Genesis 2 RGB cable with C-Sync, so i made my own in paint.. could this work? =O

(https://i.imgur.com/h87q4wZ.png)