Author Topic: CPC464 loss of display stability  (Read 1279 times)

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Offline Animalgril987

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CPC464 loss of display stability
« on: 17:56, 06 December 20 »
Hi.
I'm hoping someone can help with an issue I'm having with a 464 that I rescued from a well known auction website.


After cleaning of all the grime, and repairing the tape deck. I used an active scart lead to connect to a flat screen, and got a lovely stable display. However after a couple of minutes, I get yellow dots crawling up the screen, and the display flickers every couple of seconds.
Any ideas guys ( and gals)?

Offline Bryce

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Re: CPC464 loss of display stability
« Reply #1 on: 19:32, 06 December 20 »
Sounds more like a TV syncing issue. Is there another TV you can test the CPC and cable on?

Bryce.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #2 on: 20:25, 06 December 20 »
That was my first thought, but surely it would be unstable from the start, not have a couple of minutes of stability?


I was thinking maybe it's something in the CPC getting warm and causing the issue? With the case open, I've noticed the gate array getting warm quite quickly. It has an aluminium plate clipped to it, so I assume it's a 40007?


I have a monitor ( strangely it came with a CTM644, not a 640) I can try it with, but not until next weekend, due to work etc. The same goes with using another TV, the only other one we have is our main TV.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #3 on: 10:30, 12 December 20 »
Hi Bryce.
I tested on our main TV, and there was no instability, even after about 30 minutes.
I then connected the (now warmed up) 464 to the TV that I'm hoping to use with it and got the instability straight way.
I hope that you can advise on a solution, as using the Amstrad monitor, or the main TV are not really feasible.

Also. Neither TV displays a picture ( just a grey screen) if the active scart cable isn't powered.



As well as SCART, the TV I want to use also has HDMI, Mini YPbPr,  Mini AV/YPbPrRL , VGA (connected to my Windows PC), Coax Audio, and RF input.


Thanks in advance.


Alan.
« Last Edit: 12:11, 12 December 20 by Animalgril987 »

Offline Bryce

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Re: CPC464 loss of display stability
« Reply #4 on: 11:38, 12 December 20 »
The active bit of the SCART cable just tells the TV that you are using the RGB input of the SCART (SCART has 3 different inputs). If you can manually set the TV to RGB, then you don't need the active part.

As for the TV that doesn't sync, there's not much you can do about that without adding more hardware in between. The TV you want to use is obviously very choosy about the sync levels.

Bryce.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #5 on: 12:14, 12 December 20 »
Ok, thanks.
Do you know what additional hardware I need?
Or would using YPbPr be better than scart?
I suppose if it comes down to it, I could always get an MP1 modulator.



Alan.
« Last Edit: 12:17, 12 December 20 by Animalgril987 »

Offline Bryce

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Re: CPC464 loss of display stability
« Reply #6 on: 12:36, 12 December 20 »
There are many RGB to HDMI devices available, the good and bad of each has already been discussed in detail on the forum. Check some out and give one a try perhaps?

YPbPr isn't all that useful for a CPC. Good for other retro computers, but needs lots of hardware for an ok picture on a CPC.

An MP1 Modulator is the path to disappointment. UHF, especially on larger flat screen TVs is a fuzzy mess.

Bryce.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #7 on: 12:57, 12 December 20 »
Ok.
Thanks for the info.


Alan.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #8 on: 14:20, 12 December 20 »
I have ordered a Scart RGB to hdmi converter.
Hopefully it will arrive tomorrow.
I'll let you know how it goes.
I take it that the scart cable won't need to be powered?


Alan.

Offline Bryce

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Re: CPC464 loss of display stability
« Reply #9 on: 14:30, 12 December 20 »
Unlikely.

Bryce.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #10 on: 19:33, 13 December 20 »
Hi Bryce.
I got a Link for Scart to Hdmi converter from Amazon.
I did have to power the scart cable to get  it working, and the unit didn't come with an Hdmi cable, but...


It Works!! Rock-steady display. :D :D


Many thanks for the advice/assistance!!




Alan.

Offline Bryce

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Re: CPC464 loss of display stability
« Reply #11 on: 10:23, 14 December 20 »
Glad you got it sorted.

Bryce.

Offline Animalgril987

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Re: CPC464 loss of display stability
« Reply #12 on: 20:34, 14 December 20 »
Yeah.
Just got to sort out the desk it's sat on now, there's more cables on view than wood!
 :D


Alan.