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General Category => Technical Support => Hardware related => Topic started by: nam9 on 00:26, 31 October 18

Title: GX4000 Jail bars or PSU issue?
Post by: nam9 on 00:26, 31 October 18

I have recently set up my GX4000 with Geralds C4CPC, a new 9v 850ma PSU and a ridiculously over-engineered Monster scart cable I picked up from a charity shop...

Well, everything boots fine, but the picture I am getting over scart has prominent vertical bars over the entire image.
Are GXs susceptible to jailbars on scart? (FYI I have a european model without RF, just Scart/Din).

I have tried 2 different 9v power adaptors... could this be a power related issue?
Pic attached... not easy to see, but very clear in person :(

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Title: Re: GX4000 Jail bars or PSU issue?
Post by: nam9 on 10:13, 31 October 18
So short answer, yes, Jailbars are an issue (unless someone wishes to suggest otherwise?).

From https://circuit-board.de/forum/index.php/Thread/15426-Amstrad-GX-4000-Bildverbesserungs-Mod/ (https://circuit-board.de/forum/index.php/Thread/15426-Amstrad-GX-4000-Bildverbesserungs-Mod/)

Same thing I see...

That link brings me to ArcadeTVs work on GX4000 video imaging, which is in a post here on CPC:

http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/gx4000-video-processing-questions/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/gx4000-video-processing-questions/)

ArcadeTV concluded that the jailbars may be a result of interference from a clock line in the DAC.

Some great examples of what could be... (https://circuit-board.de/forum/index.php/Thread/15426-Amstrad-GX-4000-Bildverbesserungs-Mod/?postID=432531#post432531) but some issues left to iron out it seems...