Hi! I have these machines:
CPC6128, no problems... great picture
6128PLUS on RGB on a TV it gives me heavy vertical lines issues, very annoying
464PLUS on RGB on a tv gives me also vertical lines, but not too much as the 6128plus
I'm using a RGB scart cable from retrocomputer shack and a jamma power supply for the 5V line
Any idea? thanks
Hi,
yes, it's due to Alan sugar scraping the last penny of profit out of the machine and removing the capacitors from the RGB outputs. Not noticable on a CRT, but it shows up on modern TVs. More info here: Dirty video on 6128 Plus RGB Scart (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/video-not-clean-on-6128-plus-rgb-scart/msg48776/#msg48776)
Bryce.
Each Plus owner should apply this fix; it's a shame to have a video signal output without "filtering" ;)
Mine actually suffers from this... I should fix it, but I am considering to use a proper CRT instead :-X
Quote from: Bryce on 09:15, 19 February 16
Hi,
yes, it's due to Alan sugar scraping the last penny of profit out of the machine and removing the capacitors from the RGB outputs. Not noticable on a CRT, but it shows up on modern TVs. More info here: Dirty video on 6128 Plus RGB Scart (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/video-not-clean-on-6128-plus-rgb-scart/msg48776/#msg48776)
Bryce.
So, should I add a 'star' of three 220 pF capacitors from ground to each RGB line?
Yes.
Bryce.
I'll Try. thanks :)
(But why on the 6128+ the issue is bigger than the issue on the 464+ ? maybe different board revisions?)
No idea. The PCBs are identical so it can only be down to the tolerances of the parts used.
Bryce.
I've been meaning to ask this question myself.
Glad there's an answer even though I did see Bryces earlier answer on the dirty picture thread a long time ago.
That's one hardware problem hopefully sorted.
Thanks everyone.