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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: lassie on August 07, 2012, 11:03:49 AM

Title: Amiga 2000
Post by: lassie on August 07, 2012, 11:03:49 AM
Hi i have 3 Amiga 2000. The 2 of them i can connect to my tv with a scart lead and they work perfect. but the last one shows only black and white screen. Are there something i can do to change it in workbench? it works fine with an old amiga monitor, i have tried 3 tv but the amiga is black and white on all of them.
Title: Re: Amiga 2000
Post by: utri007 on August 07, 2012, 12:31:05 PM
Do you have also 3 SCART cabels?

Do you see ghost picture? I would say that SCART cable that you tired is wronly wired.
Title: Re: Amiga 2000
Post by: lassie on August 07, 2012, 12:39:57 PM
Quote from: utri007;702608
Do you have also 3 SCART cabels?

Do you see ghost picture? I would say that SCART cable that you tired is wronly wired.

Hi its the same scart cable i use, i only have one that is special made for the amiga. I just use that one  between all the amigas i have :-)
Title: Re: Amiga 2000
Post by: nOw2 on August 07, 2012, 01:07:46 PM
The A2000 can develop a fault which leads to colour not being shown in some circumstances. Are you able to test on a monitor? (VGA adaptor + ECS chipset or Amiga monitor)

My A2000 shows monochrome on TVs using any A520 RF modulator (used to work in colour long ago), but still works in colour on a monitor.
Title: Re: Amiga 2000
Post by: lassie on August 07, 2012, 01:15:02 PM
Quote from: nOw2;702610
The A2000 can develop a fault which leads to colour not being shown in some circumstances. Are you able to test on a monitor? (VGA adaptor + ECS chipset or Amiga monitor)

My A2000 shows monochrome on TVs using any A520 RF modulator (used to work in colour long ago), but still works in colour on a monitor.


Hi on my old amiga monitor the colour is just fine, but with all the televisions it is black and white
Title: Re: Amiga 2000
Post by: blakespot on August 07, 2012, 01:35:26 PM
As far as I know all A2000's output greyscale via the composite out. This has been the case with the two units I've owned. It's a known thing. As far as I recall, an A520 is needed to get composite out of an A2000 -- well, short of using non-Commodore solutions.


bp
Title: Re: Amiga 2000
Post by: utri007 on August 07, 2012, 01:40:37 PM
Is it so that 2 that work are old crt tvs and non working is lcd-tv?

Are you sure that cable is wired correctly? Like this : http://www.ianstedman.co.uk/Amiga/amiga_hacks/Amiga_SCART/amiga_scart.html

Open it and check
Title: Re: Amiga 2000
Post by: lassie on August 07, 2012, 01:48:51 PM
Thanks i have a look at it :-)
Title: Re: Amiga 2000
Post by: lassie on August 07, 2012, 02:21:04 PM
Hi its the same television i have tried, all crt
Title: Re: Amiga 2000
Post by: Darrin on August 07, 2012, 03:31:18 PM
PAL v NTSC models?  Amiga monitors don't care and will display both, but your TV might only support one mode.
Title: Re: Amiga 2000
Post by: Zac67 on August 07, 2012, 08:19:04 PM
On RGB it doesn't matter whether NTSC or PAL, there's no color encoding at all.

The only way to get monochrome is with composite (which doesn't come out of the DB-23 port) or a (very strange) short between R, G, and B...

Is the picture slightly blurred (=composite) or really crisp?
Title: Re: Amiga 2000
Post by: lassie on August 07, 2012, 09:19:39 PM
hi i would say the picture is very crisp
Title: Re: Amiga 2000
Post by: Zac67 on August 07, 2012, 09:44:52 PM
Hmm...

Pin 22 carrying +12V?

Pins 3, 4, and 5 separated by ~150 Ohms?

Possibly some kind of modification from a previous owner?
Title: Re: Amiga 2000
Post by: Digiman on August 08, 2012, 01:32:17 AM
Amiga SCART RGB and 1084 monitor lead use the same pins and same signals for image generation so the only thing that makes sense is a grounding issue as your monitor uses 9 pin D connector? (SCART has more than 1 ground pin but 9 pin monitor cable has just 1 IIRC).
Title: Re: Amiga 2000
Post by: TomJ on August 08, 2012, 01:53:53 AM
the composite is black and white out on 500's and 2000's I don't know why they changed it the 1000's had color. I will look for an old article telling how to modify it.
Title: Re: Amiga 2000
Post by: Zac67 on August 08, 2012, 07:22:41 AM
Composite is black and white because Vidiot lacks a color encoder.
Title: Re: Amiga 2000
Post by: danbeaver on August 08, 2012, 09:25:40 AM
"V Idiot?"
Title: Re: Amiga 2000
Post by: Zac67 on August 08, 2012, 07:05:20 PM
Vidiot (http://en.wikipedia.org/wiki/Amiga_custom_chips#Vidiot) ;)
Title: Re: Amiga 2000
Post by: psxphill on August 09, 2012, 01:17:34 AM
Quote from: TomJ;702653
the composite is black and white out on 500's and 2000's I don't know why they changed it the 1000's had color. I will look for an old article telling how to modify it.

You wouldn't use the A1000's composite video by choice. It's bad, worse even than an a520.

 
On the a500/a2000 they had to generate the composite sync, adding the monochrome video to it is cheaper than colour. Without the colour signal interfering text will be more readable.
 
If you were doing video you'd get an expensive external broadcast quality convertor, and any mixing/genlock you'd want to do before the conversion.
 
If you had an A2000 then you'd normally also have a decent monitor. An RGB scart lead should be equivalent.