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General Category => Technical Support - General => Topic started by: Prox on 19:03, 05 March 19

Title: CPC 464 video Flickering on Modern TV
Post by: Prox on 19:03, 05 March 19
I'm using my CPC 464 with a simple SCART Adapter i got from Ebay. it worked perfectly fine on an actual CRT (though i don't own it and only used it for that test so i cannot keep using it).
but when i try it with my more modern Flatscreen TV it has this strange flickering where the entire image shifts to the left for a split second.


here is a GIF of how it looks: [size=78%]


I also tested the CPC on the Monocrome screen that it came with, there the picture is perfectly stable (but sadly small and colorless).


the TV itself has very little options in terms of signal processing (or receiving?) the most i can do is change the aspect ratio, which has no effect and 16:9 worked perfectly fine on the real CRT too[/size]
Title: Re: CPC 464 video Flickering on Modern TV
Post by: VincentGR on 23:12, 05 March 19
You must give some voltage to the scart, there are some diagrams around here.
Title: Re: CPC 464 video Flickering on Modern TV
Post by: tjohnson on 00:10, 06 March 19
Maybe the 12v mod to tell the tv to use RGb mode?
See here http://www.cpcwiki.eu/index.php/TV_SCART_cable or here http://www.cpcmania.com/Docs/Scart/Scart.htm
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Prox on 05:49, 06 March 19
Quote from: tjohnson on 00:10, 06 March 19
Maybe the 12v mod to tell the tv to use RGb mode?
See here http://www.cpcwiki.eu/index.php/TV_SCART_cable (http://www.cpcwiki.eu/index.php/TV_SCART_cable) or here http://www.cpcmania.com/Docs/Scart/Scart.htm (http://www.cpcmania.com/Docs/Scart/Scart.htm)


the only thing that requires 12V on a SCART connector though is to tell it what aspect ratio to use. acording to wikipedia to use RGB Mode it needs 3V. which can be grabbed via a pass through from the Power connector of the CPC


also isn't the fact that i get a color picture at all an idicator that it already uses RGB Mode?


anyways i think the best thing to do is just to get an active SCART adapter. i found one on Ebay for 11 EUR. LINK (https://www.ebay.de/itm/Amstrad-CPC-464-664-6128-RGB-Video-Audio-Scart-Active-Cable-1m/273385308859?hash=item3fa708c2bb:g:bEIAAOSwiq9bY0Bw&frcectupt=true)
i could also just add some cables to the adpater i already have but just buying a new one is cheaper, takes less time, and the guy who made the one i have used a lot of hot glue in the SCART connector.


thanks for the help though, i didn't know i needed an active adapter for modern TVs and almost thought something broke.



Title: Re: CPC 464 video Flickering on Modern TV
Post by: tjohnson on 11:03, 06 March 19
Quote from: Prox on 05:49, 06 March 19

the only thing that requires 12V on a SCART connector though is to tell it what aspect ratio to use. acording to wikipedia to use RGB Mode it needs 3V. which can be grabbed via a pass through from the Power connector of the CPC


also isn't the fact that i get a color picture at all an idicator that it already uses RGB Mode?


anyways i think the best thing to do is just to get an active SCART adapter. i found one on Ebay for 11 EUR. LINK (https://www.ebay.de/itm/Amstrad-CPC-464-664-6128-RGB-Video-Audio-Scart-Active-Cable-1m/273385308859?hash=item3fa708c2bb:g:bEIAAOSwiq9bY0Bw&frcectupt=true)
i could also just add some cables to the adpater i already have but just buying a new one is cheaper, takes less time, and the guy who made the one i have used a lot of hot glue in the SCART connector.


thanks for the help though, i didn't know i needed an active adapter for modern TVs and almost thought something broke.


You may not need an active one my cpc works on my Sony bravia and sharp aquos with a normal cable but I guess every TV is different
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Prox on 15:03, 06 March 19
Eh rather get an active cable just to be sure so that it works on all TVs
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Bryce on 16:04, 06 March 19
In many cases you can make an active SCART cable without needing an external power source: http://www.cpcwiki.eu/index.php/TV_SCART_cable#Alternative_RGB_Wiring
This cable uses a capacitor to create the voltage required to keep the TV in RGB mode.

Bryce.
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Prox on 05:30, 08 March 19
ok if i can get through the largest blob of hot glue that i've ever seen then i might be able to solder on a capacitor.


if that doesn't work then i'll just stick to the original idea of ordering an active cable
Title: Re: CPC 464 video Flickering on Modern TV
Post by: chinnyhill10 on 09:44, 08 March 19
Quote from: Prox on 05:30, 08 March 19
ok if i can get through the largest blob of hot glue that i've ever seen then i might be able to solder on a capacitor.


if that doesn't work then i'll just stick to the original idea of ordering an active cable


Retro Computer Shack now sells active CPC RGB SCART leads after I requested them some time ago. Work well.


https://www.ebay.co.uk/itm/261898189777
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Prox on 12:48, 08 March 19
ok so, i've made the modifications to the cable i already have and it seems to be working fine.


here is how it looks: LINK (https://i.imgur.com/gCWL19I.jpg)


Thanks for all the help, people are quite nice on here.


on a completely unrelated note. the Edge connector adapter i made (This thing (https://i.imgur.com/nRoWgyq.jpg)) is aparently so horribly soldered that the CPC crashes the instant i put it in. but i used my multimeter in continuity mode and checks all pins, there are no missing or unwanted connections... maybe i'll just order some custom made small PCB for this if there is some connection that my multimeter or i missed
Title: Re: CPC 464 video Flickering on Modern TV
Post by: chinnyhill10 on 13:00, 08 March 19
Quote from: Prox on 12:48, 08 March 19


on a completely unrelated note. the Edge connector adapter i made (This thing (https://i.imgur.com/nRoWgyq.jpg)) is aparently so horribly soldered that the CPC crashes the instant i put it in. but i used my multimeter in continuity mode and checks all pins, there are no missing or unwanted connections... maybe i'll just order some custom made small PCB for this if there is some connection that my multimeter or i missed


Someone has gone a bit mad with the hot snot!
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Bryce on 13:35, 08 March 19
Quote from: Prox on 12:48, 08 March 19
ok so, i've made the modifications to the cable i already have and it seems to be working fine.


here is how it looks: LINK (https://i.imgur.com/gCWL19I.jpg)


Thanks for all the help, people are quite nice on here.


on a completely unrelated note. the Edge connector adapter i made (This thing (https://i.imgur.com/nRoWgyq.jpg)) is aparently so horribly soldered that the CPC crashes the instant i put it in. but i used my multimeter in continuity mode and checks all pins, there are no missing or unwanted connections... maybe i'll just order some custom made small PCB for this if there is some connection that my multimeter or i missed

With a bonus 3pf of capacity just from the length of those leads :)

Bryce.
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Prox on 19:35, 08 March 19
Quote from: Bryce on 13:35, 08 March 19
With a bonus 3pf of capacity just from the length of those leads :)

Bryce.



to be honest they had to be that long to fit into the SCART connector... damn hot glue taking up so much space
Title: Re: CPC 464 video Flickering on Modern TV
Post by: Bryce on 10:04, 09 March 19
I know, the SCART cable slopes up on that side, it was just a funny comment for entertainment value. :)

Bryce.
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