Modification to have RGB on the Amstrad MP3 TV tuner

[Orko Ready]

Hello, I made the modification to have RGB on the Amstrad MP3 TV tuner. But the image is shaking (see video), any idea of the problem?

[Orko Ready]

Amstrad mp3 tuner, wiring.

[SerErris]

So you try to put a SNES to the CTM-644 monitor?

If I see your connections (and I have not reviseted the schematic for the MP-3 yet), then you just transport the 3 RGB signals. How do you transport the SYNC?

[SerErris]

And now after looking at the schematic - it does not match your device. The schematic I have from the amendment service manual does not have a SCART port ... 

Can you take a picture from the Amstrad Model Number ? It is hidden by the blue wires from the picture above.

Also do you have a schematic of the device?

[SerErris]

According to this video your wiring looks correct,

however the scart connector also looks like it could make connection in between the pins. 

Next step, I would check the sync signal on both ends, if it is a good signal. If it is good on the Scart connector, but not on the CPC, you have anything in between not working correctly. 

Also I am not sure if the sync from the SNES is compatible with the CPC monitor. 

[Orko Ready]

Thank SerErris for your help.
Yes that's right, I want to make a CTM-644 and SNES connection with the MP3 Tuner.
Model number is PT NO Z80258
On FB i am advised to weld a condo on 18 to 16.

[Bryce]

For a functioning RGB connection you definitely need to connect the sync signal, but I would also recommend connecting the Grounds from one connector to the other. The capacitor between 16 and 18 is there to create a voltage that will let the TV know that SCART RGB is the selected input.

@SerErris : The SCART output was only available on French devices as far as I know. The schematics found online are usually for UK or DE devices.

Bryce. 

[Orko Ready]

I tried with the master system II, it works well.

[SerErris]

There is just one question,

why do you even use the converter, if you just could solder the RGB signals directly to the CTM644?

That would be a Scart female connector to the 6 pin DIN female connector. So actually the opposite cable you would need to connect a CPC to a TV via Scart Cable.

You are actually using this box with a lot of electronics that does nothing in the end.

What was your solution to the original task? And do you have the schematics of the French MP3?

[pelrun]

"I already have a box that fits perfectly under the CTM644 with the right monitor plug and a SCART connector on the back, why monkey around with custom cables?"

[Orko Ready]

There is just one question,

why do you even use the converter, if you just could solder the RGB signals directly to the CTM644?

That would be a Scart female connector to the 6 pin DIN female connector. So actually the opposite cable you would need to connect a CPC to a TV via Scart Cable.

You are actually using this box with a lot of electronics that does nothing in the end.

What was your solution to the original task? And do you have the schematics of the French MP3?

In the Mp-3 there is also an antenna socket which works well with old consoles, it is for the practical side, the 2 in 1.

For the moment the master system II works very well and I still have a sync problem with the snes.

I don't have any MP-3 French diagram

[Orko Ready]

"I already have a box that fits perfectly under the CTM644 with the right monitor plug and a SCART connector on the back, why monkey around with custom cables?"

To connect consoles

[dragon]

The french mp-3 only accept secam-L. The only console that work with  he was  the french atari SECAM out of the box.

About snes,maybe you can try a diferent cable of snes to scart, instead of composite Sync, Sync on luma.


Maybe work or not...

In order to Connect a rca(pal) Signal to the french mp-3 scart  you need search and buy a Sony sfr-1000 thats is a old pal to SECAM -L Converter.

[Swarmadd]

Hello, I don't have a MP-3 tuner but maybe I could help, as I see the sync is problematic, above all the horizontal one (The quick left/right shaking). And you have a Vsize problem (Picture squashed) but I guess that's supposed to happen as I encountered that problem without tuner.

In my case I can use my CTM644 with MD, SNES, and CPCs just with a scart as I replaced the DIN

But most importantly I had to replace and move some pots next to brightness for quick (and non-lethal ) access to Hsync, Vsync and Vsize




With a CPC (Of course!) or any SNES (Super Nintendo or Super Famicom jr) with an official pal cable and sync on luma, everything is perfectly fine.
My only remaining issues are related to low brightness and weak signal with megadrive and snes when using low quality ntsc cables, so I guess that's a cable / rgb signal "strength" issue and not a sync one, but I suspect grounding as Bryce said.

To begin I'd check the scart cable of the console on its sync side then the Hsync (H.Hold). Maybe your MP-3 have these same trimpots on its pcb ?