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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: pdiggitydogg on October 17, 2015, 06:50:17 AM

Title: Sync trouble
Post by: pdiggitydogg on October 17, 2015, 06:50:17 AM

I recently finished modding my super CD rom2 for rgb, using an amp from a member here. I used a mini din 9 connector, from a model 2 Genesis. Everything works....mostly.
I'm running the Scart leads through a Hama splitter, along with Scart leads from my Sega Saturn and model 1 genesis. From the splitter, into pure sync rgb cable and into a DVDO vp30 scaler.
The Sega units work perfectly, on their own...
The pce only displays a picture when either Sega unit is on...without, there is no picture! I have no cross talk between anything, or so I thought.
What the heck??

I am pulling sync from the sync pin, at the expansion port. Should I try composite video instead? Composite video is currently tapped at the av jack, along with audio - because reasons.

Title: Re: Sync trouble
Post by: Keith Courage on October 17, 2015, 07:37:12 AM

 I've always used composite video out for sync. Try that.

Title: Re: Sync trouble
Post by: pdiggitydogg on October 18, 2015, 06:36:16 AM

Ok, I tried composite video to the sync pin - same issue.
I tried alternative ports on the Hama with no change. Neither Sega unit has affect on the other, when they are on...

Oh. I should also mention that the cable that I am using works with my Sega Nomad without issues.

Title: Re: Sync trouble
Post by: pdiggitydogg on October 18, 2015, 06:55:09 AM

Agh! It was the 5v...
I had a good connection, but for some reason the av jacknis only showing 0.5v. Tapped 5v at the expansion port and its working. I am guessing the Hama has a 5v bar shared across everything, no matter what.

Title: Re: Sync trouble
Post by: GohanX on October 18, 2015, 06:57:28 AM

Btw, unless the amp was specifically built with Sega cables in mind you may not be getting optimum picture.  Sega cables gave resistors and caps on the rgb lines.

Title: Re: Sync trouble
Post by: pdiggitydogg on October 18, 2015, 11:19:59 AM

It's an aftermarket cable from retroconsoleaccessories, not the pal Scart lead

Title: Re: Sync trouble
Post by: Ergot_Cholera on October 18, 2015, 09:44:01 PM

The 5v line to the din 5 socket of the Super CD-ROM² is not connected (at least it wasn't on mine). I had problems with RGB and fast blanking switching until I realised this.

Title: Re: Sync trouble
Post by: pdiggitydogg on October 19, 2015, 07:37:50 AM

That's interesting. I am getting some voltage at mine, but clearly not much.
There is a pad there, connected to a resistor, I believe (?)