Amstrad CPC 6128 Plus Display Issues

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terriblefire
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Amstrad CPC 6128 Plus Display Issues

Post by terriblefire »

I've got an Amstrad CPC 6128 Plus up and running but i'm seeing ghosting with the scart cable. I'll try and get an image captured tomorrow but its ghosted a few lines and i have hsync issues too. The whole picture usually looks complete but jumps around and has ghosting..
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alexh
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Re: Amstrad CPC 6128 Plus Display Issues

Post by alexh »

I had to drive the RGB Blanking signal from a separate 5v power supply to make mine work well. Sometimes described in CPC circles as an active SCART cable

https://www.ebay.co.uk/itm/251970455548
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terriblefire
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Re: Amstrad CPC 6128 Plus Display Issues

Post by terriblefire »

Ah ok i'll try that out. My 5v supply used for this test is perfect but i guess the 5v rail is not decoupled on the CPC because there is no regulator on board.

EDIT: ah man. seller is shut for holidays..
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indicates how much hurting you shall receive."
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Re: Amstrad CPC 6128 Plus Display Issues

Post by alexh »

https://coolnovelties.co.uk/coolnovelti ... cable.html

The problem is there is no power voltage pin on the CPC 6128 plus video port. Just RGBS and most passive cables make the RGB Blanking voltage using a capacitor. Replacing this with a battery or dedicated external voltage is known to fix it

http://www.cpcwiki.eu/forum/amstrad-cpc ... t-monitor/
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Re: Amstrad CPC 6128 Plus Display Issues

Post by alexh »

My passive cable worked fine with my Phillips CM8833 but had ghosting and sync issues with my Panasonic Plasma. I bought an active cable and it was fixed. To be fair the cable is a different length so the ghosting might be the cable length. Or it might have been wired with more grounds than the passive cable. Definitely worth a test, easy for you to mod your existing cable.
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terriblefire
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Re: Amstrad CPC 6128 Plus Display Issues

Post by terriblefire »

I'll grab one from that supplier when the holidays are over.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
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