Author Topic: Vertical lines on Plus  (Read 838 times)

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Offline davdav79

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Vertical lines on Plus
« on: 05:15, 19 February 16 »
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

Offline Bryce

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Re: Vertical lines on Plus
« Reply #1 on: 10:15, 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

Bryce.

Offline Kris

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Re: Vertical lines on Plus
« Reply #2 on: 10:40, 19 February 16 »
Each Plus owner should apply this fix; it's a shame to have a video signal output without "filtering" ;)


Offline ||C|-|E||

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Re: Vertical lines on Plus
« Reply #3 on: 10:50, 19 February 16 »
Mine actually suffers from this... I should fix it, but I am considering to use a proper CRT instead  :-X

Offline davdav79

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Re: Vertical lines on Plus
« Reply #4 on: 11:58, 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

Bryce.

So, should I add a 'star' of three 220 pF capacitors from ground to each RGB line?

Offline Bryce

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Re: Vertical lines on Plus
« Reply #5 on: 12:22, 19 February 16 »
Yes.

Bryce.

Offline davdav79

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Re: Vertical lines on Plus
« Reply #6 on: 13:30, 19 February 16 »
I'll Try. thanks :)

(But why on the 6128+ the issue is bigger than the issue on the 464+ ? maybe different board revisions?)

Offline Bryce

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Re: Vertical lines on Plus
« Reply #7 on: 14:31, 19 February 16 »
No idea. The PCBs are identical so it can only be down to the tolerances of the parts used.

Bryce.

Offline seanb

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Re: Vertical lines on Plus
« Reply #8 on: 13:13, 20 February 16 »
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.
Thou shall not question Captain Wrong!