GX4000 and C4CPC problem

[davdav79]

Hello.
I have a CPC6128+ and a GX4000. And a C4CPC.
I have also a CM14 monitor, but sometimes I like to play on tv, so I bought  CPC+ RGB cable and a power supply (5V 3A regulated).
So this is the situation:
monitor + 6128plus and c4cpc = good
monitor + gx4000 and c4cpc = good
tv + 6128plus (with rgb cable and the regulated power supply 5V) and c4cpc = good
tv + gx4000 (with rgb cable and the regulated power supply 5V) and c4cpc = trembling image (with a normal cart = good)

I measured the voltage on the power supply during the power on and it gives 5V.
Solution? thanks

[chinnyhill10]

Put 1.5v on the SCART select pin or add a capacitor to that pin in the SCART socket and it will be OK.

[davdav79]

Why the different behaviours ?

[Bryce]

If the only hardware difference is the C4CPC then it has nothing to do with the cable and the 1.5V Battery won't make a difference to picture quality. I assume you measured the 5V with a multimeter, but the power could still be dropping for milliseconds or just be very noisy when it has a heavier load on it. I'd try a more powerful PSU first.

Bryce.

[chinnyhill10]

If the only hardware difference is the C4CPC then it has nothing to do with the cable and the 1.5V Battery won't make a difference to picture quality.

If you boot to the menu, the overscan mode the device boots to seemed to 'trip' out my TV before I added the 1.5v. Also large areas of peak white. Was fine the rest of the time.

[gerald]

Why the different behaviours ?

Some possibilities :
- A gx4000 will consume a bit less than a Plus and with a 3A power supply, you may have load regulation issues.
- The GX4000 has a slightly different way of powering the video output. Combined the the PSU, output level may be different enough to make the TV unhappy.

Ideally, I would need the full TV/Cable/PSU/GX/Plus to make a diagnostic 

Can you identify your cable wiring in this page?
Can you post a picture of the problem ?

[Bryce]

If you boot to the menu, the overscan mode the device boots to seemed to 'trip' out my TV before I added the 1.5v. Also large areas of peak white. Was fine the rest of the time.

Yes, but then he would have the same issue on his plus.

Bryce.