6128 Plus Picture issue on Sony PVM

[beaker]

Can anyone help, I've still got issues with my 6128+. I had the membrane replaced so they keyboard is working but the image quality on my Sony PVM is shocking as can be seen in the picture compared to the Pioneer Plasma TV. Anyone got any ideas what it might be? I've replaced the home made scart cable with one from CoolNovelties but the image is exactly the same. I have the original monitor in the loft I can bring down to test out on but I was hoping to use it with the Sony PVM which I use for about 40 other machines no problem...

[beaker]

Here's it running an Oric and C64 over the last week to prove the TV is fine...

[Bryce]

Hi beaker,
     sorry, missed this thread for some reason. How do other computers that use RGB look on the PVM. I assume the Oric and C64 are using different inputs?
It looks like you have capacitance on the RGB lines that's making the colours run.

Bryce.

[beaker]

Hi Bryce,

No worries, thanks for responding 

The Oric is using the RGB scart like the 6128+ but the C64 is using S-Video. I was also testing the Dreamcast tonight which uses the RGB scart and that seems fine as well.

[attach=2] [attach=3]

and an RGB modded NES using the scart

[attach=4]

Roy Bates also suggested caps on Amibay...

Andy, from CoolNovelties got back to me on Thursday saying

I've checked our wiring diagram for the Amstrad plus cable.  We use luminance as the video input signal which is more compatible with standard TVs, but on your Sony PVM I would imagine it would prefer Composite SYNC or Composite Video.  This *could* be the problem.  You could try swapping over the wire from the centre pin (purple) with the yellow wire which is composite SYNC.  This may cure the problem for you.   There are no resistors on the colour lines or video output, just a capacitor on the blanking (RGB switching) pin.

I know the monitor can use an external sync or syncs on green, if that makes any difference?

[kevin.c]

Hi beaker,
about 6128+ and Sony issue: try to solder 3 terminating resistors 100 Ohm on each of RGB lines. You can do it inside SCART connector case, directly to the pins. Pin 15 is Red, and 13 -Red's ground. Green 11, ground on 9. Blue  7, ground  on 5.

I know the monitor can use an external sync or syncs on green, if that makes any difference?

No difference. "Sync on green" was developed just to spare 4-th sync cable.

[roy bates]

i never mentioned caps bud,if i remember correctly

try the resistor method from above,and switching in the composite sync for luma,i think that monitor will be expecting that instead.

[beaker]

lol, sorry my bad. I'm not really technically minded so easily confused 

[Bryce]

Ah, you don't have the resistors installed? You really need them on the PVM (on Atari ST too).

Bryce.

[beaker]

Thanks all, that's great to know as the ST RGB lead I have from Retro Computer Shack is pin sharp on the PVM so must have them in :thumbsup: