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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: amigalover on February 19, 2010, 10:58:37 PM

Title: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 19, 2010, 10:58:37 PM
Can somebody help me please? I´ve got an Amiga 1200, and have a problem with video output. When I connect the Amiga via the composite video out jack ( labelled COMP ) to the video-in input of my TV ( it is a NTSC japanese TV but in my country we use PAL system ), the image is sharp and clean, but is all greenish, and does not show the other colors, what could be going on ? something has gone wrong with my Amiga video ? I would be very grateful for someone´s help as there is no Amiga service in my country now to ask.:(
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 12:04:06 AM
First of all, check you are doing things right:

1-Check (do not assume) wether your Amiga is either PAL or NTSC
2-Make sure your Amiga TV standart matches BOTH your Tv and your A1200
3-Connect the A1200 to a TV using the RF output. and check if it works properly
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 12:26:44 AM
Quote from: Gulliver;544019
First of all, check you are doing things right:

1-Check (do not assume) wether your Amiga is either PAL or NTSC
2-Make sure your Amiga TV standart matches BOTH your Tv and your A1200
3-Connect the A1200 to a TV using the RF output. and check if it works properly


Thanks for your answer, but how do I know wether my Amiga is Pal or NTSC ? Is there an indication anywhere in the computer ?. The thing is that I always used the Amiga 1200 connected to a VGA monitor via a VGA adaptor and worked fine that way, and never needed to connect it to TV. Now I had a problem with my hard disk and the Amiga only boots from the floppy drive, so I have no way but to try it usign a TV set, and found this problem that the image is greenish and not in color. I also connected the A1200 using the RF output to a scart connection to the antenna, but it was worse, I had no image on the TV using the RF output. I have read in the manual that if a TV is Pal I have to turn on channel 36 and tune a screw near the RFT modulator of the A1200 until the picture is clear ? Maybe I did not try that and that is the reason I don´t see any image using the RFT ? I wish I had my hard disk working ! it was far more easy to proceed ... Do I try that procedure ? ( channel 36 and so )...waiting for your next answer...thanks!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 12:43:02 AM
To check wether your Amiga is PAL or NTSC, do the following:

1-Carefully open your A1200 and have the motherboard exposed
2-Search in the motherboard for an oscillator wich is labeled on the motherboard as X1. The Oscillator is a rectangular 1cmx2cm aprox. metal object, located in the center of your motherboard.
3- If on top of the Oscillator you read 28.63636, then your Amiga is NTSC. If it says 28.37516, then it is PAL

By the way, I have never heard about that channel 36 weird trick!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: ElPolloDiabl on February 20, 2010, 04:56:40 AM
Composite is monochrome output on the Amigas, not sure why. You need to connect it to the RF out/TV out.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 05:16:56 AM
@Fanscale
You are wrong: the A600 and A1200 will output composite in color, not monochrome!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: delshay on February 20, 2010, 02:50:04 PM
why are you not using the A1200 RGB output? your tv can't be that old or is it.

those outputs do my eyes in i will never look at anything lower than S-VID,which is bulit into my motherboard.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: spaceman88 on February 20, 2010, 02:54:33 PM
Quote from: Fanscale;544039
Composite is monochrome output on the Amigas, not sure why. You need to connect it to the RF out/TV out.


No, the 1200 has colour output on composite. It's probably a PAL 1200 on a NTSC  monitor, some monitors will "roll" others will have no colour others won't show anything at all if you have a PAL/NTSC mismatch. You could try holding down both mouse buttons when you turn it on and go into the boot menu and select "NTSC" and boot. Not 100% sure that will fix your problem, but it's worth a shot.
Len
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 03:42:37 PM
@spaceman88

booting an Amiga and changing in the early boot menu (by holding both mouse buttons) from PAL to NTSC or vice versa, will not help. Let me give you the long explanation:

Video signals for television in North America are different from
those used in Europe. North America uses the NTSC system, and most
European countries, as well as many others, use the PAL system. Since
the Amiga uses video-based screen modes, they are made for the different
modes according to the country.

The main differences between the two modes are resolution and frame
rate. NTSC displays have 200 lines vertically, or 400 in interlaced
mode, and displays 29.97 frames (59.94 fields) per second (most people
round it off to 30). PAL uses 256, or 512 interlaced, with a frame rate
of 25 frames per second (50 fields).

If you have the ECS chipset, you can switch your display between the two
modes using the Screenmode Prefs program, in the Prefs drawer. You can
also switch from the default screenmode at boot time with the Early
Startup Menu, which you access by holding down both mouse buttons when
booting.

Some programs, most notably games, which are not fully OS-compliant,
only support one of the modes. Many of the games on Aminet, for example,
are PAL only. If you have an NTSC machine, you will be able to use most,
but not all, of them as long as you have the ECS or AGA chipset and at
least 1 MB of CHIP RAM.

This method of switching to NTSC or PAL modes is only used to make
software work which is designed for the other standard. It's not
sufficient if you want to use an Amiga with hardware video equipment
from the other standard. For this purpose, you would have to rework your
Amiga's motherboard to a high degree, e.g. change the main crystal and
the modulator.

Hope it helps you to understand it! :)
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 03:56:52 PM
Quote from: Gulliver;544024
To check wether your Amiga is PAL or NTSC, do the following:

1-Carefully open your A1200 and have the motherboard exposed
2-Search in the motherboard for an oscillator wich is labeled on the motherboard as X1. The Oscillator is a rectangular 1cmx2cm aprox. metal object, located in the center of your motherboard.
3- If on top of the Oscillator you read 28.63636, then your Amiga is NTSC. If it says 28.37516, then it is PAL

By the way, I have never heard about that channel 36 weird trick!


Hello again. I opened my Amiga 1200 and checked the motherboard for the oscillator you mention, it says 286363 MH so mine is an NTSC Amiga.
The TV I´m trying is a modern NTSC japanese or korean Goldstar, but it might have been adapted by the service, to Pal system, which is the TV system we use in my country, could that be the reason why I see the image all greenish ? I tried also with the A520 modulator which comes with the Amiga 500, connected it to the Video output ( the connection with pins ) of my A1200, and I obtained either a greenish image again or a black and white image if I move the switch that is above. Is it normal to see the image black and white or greenish instead of full color on a TV ? Thanks in advance.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 04:04:53 PM
Quote from: spaceman88;544073
No, the 1200 has colour output on composite. It's probably a PAL 1200 on a NTSC  monitor, some monitors will "roll" others will have no colour others won't show anything at all if you have a PAL/NTSC mismatch. You could try holding down both mouse buttons when you turn it on and go into the boot menu and select "NTSC" and boot. Not 100% sure that will fix your problem, but it's worth a shot.
Len

Hello. Thanks for your quote. I followed the instructions of "Gulliver" and discovered my Amiga is NTSC, seeing the number in the oscillator, but I don´t know wether to consider my TV as NTSC or PAL, as it is a modern Goldstar made in Japan or Korea and I suppose it is NTSC, but as we use the Pal television system in my country it probably must have been adapted to PAL by the service. My A1200 came with a Seagate hard disk and I always used a VGA monitor with no problem, but now my hard disk is dead and I had to boot from the floppy drive for the first time and found the above mentioned problem, which is seeing the image sharp but greenish or black and white, don´t know what to do or if this is normal, there is no Amiga service in my country to ask nowadays.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 04:22:25 PM
Quote from: delshay;544071
why are you not using the A1200 RGB output? your tv can't be that old or is it.

those outputs do my eyes in i will never look at anything lower than S-VID,which is bulit into my motherboard.

Hello. By RGB output do you mean the RFT output or that I have to use a scart/RGB adapter cable attaching the 23 pin video output of the Amiga to a TV antenna ?
I already tried the RFT jack connected via a scart to TV and had no image, but I didn´t try moving the black switch which is near the RFT output of the A1200 and turns NTSC to PAL and viceversa, but the manual mentions I have to put channel 36 in TV while doing that ? I read it in the A1200 user´s guide. I also tried the A520 modulator that comes with the Amiga 500, attached to the 23 pins video output of the Amiga 1200 and used a video cable going from the video out of the modulator to the video in of the TV, but obtained again either a greenish image or a black and white image, depending the way I moved the switch which is above in the modulator, so it´s the same result I had previously obtained by connecting directly to the composite video jack of the A1200.
Thanks in advance for your explanation.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 04:27:37 PM
Quote from: amigalover;544084
Hello. By RGB output do you mean the RFT output or that I have to use a scart/RGB adapter cable attaching the 23 pins video output of the Amiga to a TV antenna ?
I already tried the RFT jack connected via a scart to TV and had no image, but I didn´t try moving the black switch which is near the RFT output of the A1200 and turns NTSC to PAL and viceversa, but the manual mentions I have to put channel 36 in TV while doing that ? I read it in the A1200 user´s guide. I also tried the A520 modulator that comes with the Amiga 500, attached to the 23 pins video output of the Amiga 1200 and used a video cable going from the video out of the modulator to the video in of the TV, but obtained no image!
Thanks in advance for your explanation.

Sorry, I made a mistake in my explanation, using an A520 modulator I obtained either a greenish image or a black and white image depending the way I moved the switch wich is above in the modulator, so the same result I had obtained by connecting directly to the composite video jack of the A1200.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 04:31:25 PM
Quote from: delshay;544071
why are you not using the A1200 RGB output? your tv can't be that old or is it.

those outputs do my eyes in i will never look at anything lower than S-VID,which is bulit into my motherboard.


Sorry, I made a mistake in my previous explanation, using an A520 modulator I obtained either a greenish image or a black and white image depending the way I moved the switch wich is above in the modulator, so the same result I had obtained by connecting directly to the composite video jack of the A1200.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Homer on February 20, 2010, 05:34:08 PM
Hi amigalover,

Which country are you in ?
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 06:10:35 PM
Quote from: Homer;544094
Hi amigalover,

Which country are you in ?

Hi Homer

I live in Uruguay, South America
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 06:28:29 PM
Why dont you try your Amiga with another TV? Preferably a relatively modern one, these are nearly allways supporting PAL and NTSC alltogether, you just need to pull a switch or access the OSD menu of the TV and change its configuration.
You must be sure which TV standart is actually using your TV, so that we dont wrongly declare broken your Amiga built-in modulator or something else.

By the way, i am in Chile so, if you require any help you can PM me and i can talk you through this in spanish if it is easier for you.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: marcfrick2112 on February 20, 2010, 09:48:20 PM
Hi Amigalover,

I'd also suggest trying another TV. The 'greenish tint' you describe has me at a loss, but the back and white image makes me thinks it's some PAL/NTSC problem, as mentioned. Always check the simple stuff first before suspecting your Amiga. You're in Uruguay? Cool, I just sold an A500+ service manual to a guy in Uruguay.....

Good luck with getting this fixed up... and when you can, get that hard drive replaced... :)
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 10:44:22 PM
Quote from: Gulliver;544106
Why dont you try your Amiga with another TV? Preferably a relatively modern one, these are nearly allways supporting PAL and NTSC alltogether, you just need to pull a switch or access the OSD menu of the TV and change its configuration.
You must be sure which TV standart is actually using your TV, so that we dont wrongly declare broken your Amiga built-in modulator or something else.

By the way, i am in Chile so, if you require any help you can PM me and i can talk you through this in spanish if it is easier for you.

Hola, gracias por tu ayuda, no sabia que eras de Chile si no te hubiera hablado en español desde el comienzo. :)
Mi TV es moderno, es un Goldstar made in Korea, con entradas RCA video in y audio in atrás. He probado todas las formas de conectar la Amiga 1200 al televisor, la Amiga 1200 resultó ser NTSC siguiendo las indicaciones que me diste de mirar el número en el oscilador, pero el televisor supongo que será NTSC modificado a PAL. ¿ Cómo se hace para acceder al menu que mencionas en el Televisor y que permite elegir NTSC o PAL ? eso lo desconocía......A esta altura me parece que algo está mal en el chip de video de mi máquina, porque estoy seguro que hace pocos días vi la imagen por el TV a todo color, y ahora sale verdosa...tengo la máquina en venta, me da mucha pena, pero no puedo gastar mas dinero en ella, gasté una fortuna y ya no queda service en mi país, hace años que cerraron, si la conservo o encuentro otra solución te consultaré, mientras tanto me mantengo en el mundo Amiga, que no pienso abandonar, usando "Amiga Forever" con el emulador WinUAE, y WinFellow para juegos, en mi PC, no es lo mismo pero es lo mas parecido ! Gracias por todo y saludos cordiales!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 20, 2010, 10:53:54 PM
Quote from: marcfrick2112;544133
Hi Amigalover,

I'd also suggest trying another TV. The 'greenish tint' you describe has me at a loss, but the back and white image makes me thinks it's some PAL/NTSC problem, as mentioned. Always check the simple stuff first before suspecting your Amiga. You're in Uruguay? Cool, I just sold an A500+ service manual to a guy in Uruguay.....

Good luck with getting this fixed up... and when you can, get that hard drive replaced... :)

Hi

As I said to "Gulliver" from Chile my TV set is modern, it is a korean Goldstar with video in and audio in RCA jacks on the back. I am afraid the video chip of my Amiga has something wrong, it should display full color not a greenish image through the composite jack! Moreover I had my hard disk broken yesterday, lost four or five pins of the connector while trying to fix it, so I would have to replace it, just in case how much does it cost a 2.5"" Seagate hard disk with enough capacity, say more than 80 mb, nowadays ? Just to make up my mind about what to do. Thanks in advance!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 20, 2010, 11:41:43 PM
Goldstar es una marca un poco viejita, fue rebautizada a LG hace ya mucho tiempo. Lo mas probable es que el TV haya sido reconvertido a PAL y no se pueda cambiar de norma.
En todo caso, proba con el control remoto de la TV para ver si aparece algun menu en pantalla que permita hacer el cambio de PAL a NTSC.
Te ofrezco, si te interesa, un modulador A520 PAL gratis, solo te pediria que me pagues el costo de envio a Uruguay que es menor a diez dolares americanos, tendria que averiguar cuanto exactamente.

In English:
Goldstar is a little bit old brandname, it was renamed LG long ago. The most probable thing is that the TV has been reconverted to PAL and you cant change the standart.
Anyway, you should try with the remote control of the TV to see if some kind of on screen menu appears that allows you to change from PAL to NTSC.
I am offering you, if you are interested, an A520 PAL modulator for free, i will only ask you that you pay the shipping cost to Uruguay that is less than 10 USD, that i will eventually have find out the exact amount.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: amigalover on February 21, 2010, 12:18:02 AM
Quote from: Gulliver;544157
Goldstar es una marca un poco viejita, fue rebautizada a LG hace ya mucho tiempo. Lo mas probable es que el TV haya sido reconvertido a PAL y no se pueda cambiar de norma.
En todo caso, proba con el control remoto de la TV para ver si aparece algun menu en pantalla que permita hacer el cambio de PAL a NTSC.
Te ofrezco, si te interesa, un modulador A520 PAL gratis, solo te pediria que me pagues el costo de envio a Uruguay que es menor a diez dolares americanos, tendria que averiguar cuanto exactamente.

In English:
Goldstar is a little bit old brandname, it was renamed LG long ago. The most probable thing is that the TV has been reconverted to PAL and you cant change the standart.
Anyway, you should try with the remote control of the TV to see if some kind of on screen menu appears that allows you to change from PAL to NTSC.
I am offering you, if you are interested, an A520 PAL modulator for free, i will only ask you that you pay the shipping cost to Uruguay that is less than 10 USD, that i will eventually have find out the exact amount.

Si, en realidad tienes razón, dije televisor moderno pero tiene como 15 años de comprado, lo compré nuevo, me refería a que por lo menos tiene las entradas RCA de video in y audio in.
Yo tengo un modulador A520 que funciona bien de otra Amiga 500 que tenía, pero ¿ hay moduladores PAL y moduladores NTSC ? El mio no se que norma es, pero tiene una palanquita arriba, que cuando conecté el modulador a la computadora y con un cable al TV, me cambiaba el color de la imagen desde el verdoso ese que te conté a blanco y negro, nunca a colores, ¿ la palanca será para pasar de Pal a NTSC o viceversa ?
Title: Re: Amiga 1200 video output problem. Please help!
Post by: Gulliver on February 21, 2010, 07:46:52 AM
No, la palanquita es para cambiar en la salida RF la configuracion para que funcione en canal 3 o 4.
Y si, hay moduladores PAL y otros NTSC.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: ElPolloDiabl on February 21, 2010, 07:52:10 AM
Quote from: Fanscale;544039
Composite is monochrome output on the Amigas, not sure why. You need to connect it to the RF out/TV out.

I think what I did was plug the composite out of the Amiga 2000 to the RF in on the TV and got a B&W image. Must be something unique to Amiga and few consoles.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: spaceman88 on February 21, 2010, 05:08:05 PM
Quote from: Fanscale;544199
I think what I did was plug the composite out of the Amiga 2000 to the RF in on the TV and got a B&W image. Must be something unique to Amiga and few consoles.


Yes, the composite output of 2000's and 500's is B&W, the 1200 ( and I think 600) is colour.
Title: Re: Amiga 1200 video output problem. Please help!
Post by: spaceman88 on February 21, 2010, 05:25:51 PM
Quote from: Gulliver;544079
@spaceman88

booting an Amiga and changing in the early boot menu (by holding both mouse buttons) from PAL to NTSC or vice versa, will not help. Let me give you the long explanation:

Video signals for television in North America are different from
those used in Europe. North America uses the NTSC system, and most
European countries, as well as many others, use the PAL system. Since
the Amiga uses video-based screen modes, they are made for the different
modes according to the country.

The main differences between the two modes are resolution and frame
rate. NTSC displays have 200 lines vertically, or 400 in interlaced
mode, and displays 29.97 frames (59.94 fields) per second (most people
round it off to 30). PAL uses 256, or 512 interlaced, with a frame rate
of 25 frames per second (50 fields).

If you have the ECS chipset, you can switch your display between the two
modes using the Screenmode Prefs program, in the Prefs drawer. You can
also switch from the default screenmode at boot time with the Early
Startup Menu, which you access by holding down both mouse buttons when
booting.

Some programs, most notably games, which are not fully OS-compliant,
only support one of the modes. Many of the games on Aminet, for example,
are PAL only. If you have an NTSC machine, you will be able to use most,
but not all, of them as long as you have the ECS or AGA chipset and at
least 1 MB of CHIP RAM.

This method of switching to NTSC or PAL modes is only used to make
software work which is designed for the other standard. It's not
sufficient if you want to use an Amiga with hardware video equipment
from the other standard. For this purpose, you would have to rework your
Amiga's motherboard to a high degree, e.g. change the main crystal and
the modulator.

Hope it helps you to understand it! :)


Hi,
I had my doubts whether switching modes would help, but it's so easy to do I thought it would be worth a try. I use scala MM300 from a CU Amiga cover disk, which I have to boot into PAL mode to run. My TV will not display the screen until I select "NTSC output" and hit "Run" in Scala, so it may not be a true PAL signal but something changes at the composite output.
Len
Title: Re: Amiga 1200 video output problem. Please help!
Post by: tone007 on February 21, 2010, 05:27:38 PM
1000 also has color composite!
Title: Re: Amiga 1200 video output problem. Please help!
Post by: tone007 on February 21, 2010, 05:30:06 PM
Quote from: spaceman88;544243
so it may not be a true PAL signal but something changes at the composite output.

RIght, PAL mode outputs 50hz and NTSC outputs 60hz, the change that doesn't happen is the color system, so basically when you select PAL mode on an NTSC 1200, you get NTSC-50.

I have an LCD TV here that sees 50hz and assumes PAL, so when it goes into PAL mode on my NTSC machines I get no color.