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Amiga computer related discussion => Amiga Software Issues and Discussion => Topic started by: SuperTurbo on May 09, 2006, 03:51:12 PM
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I recently bought a Indivision external scandoubler for my a1200T. But sadly I can´t get any picture with it. I tested it with two different VGA monitors, and it´s just black. The store I bought it from have tested it and confirmed that there is nothing wrong with the scandoubler.
I also have a multiscan (amiga branded) monitor which works perfectly, so there´s no appearant fault with the RGB port itself.
It´s just my assumptions, but is it possible that the fault may be that the pin/pins providing power in the RGB port is not working (I´m assuming the scandoubler is consuming some amount of power)? None of the pins are physically broken though. Anyone heard of a similar problem?
I know my motherboard have a strannge bug which make my unable to use a apollo turbo, however my blizzard 060 works just fine. Also, there´s some strange flickering lines when using the DBLpal screenmode. Sorry, but I can´t seem to find the revision number of my motherboard right now. I seem to have forgotten where to look, but I assume I have to move the mediator! :-(
My specs are: a1200t, mediator (4 slots), blizzard 060 w 64mb fastmem, elbox keyboard adapter, voodoo 5, network, soundblaster + a few drives connected via idefix adapter.
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Hi,
it's not your fault !
But take a closer look to your mobo rev, and go to aminet in the hack directory to find the modification to get the missing power ;)
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I bet that your VGA monitor has trouble with low refresh rates and cannot cope with anything below 31hz, which is needed for PAL. If you were to switch to NTSC, it would probably work as NTSC scan-doubled is slightly above 31hz and pal is closer to 30hz.
Try going to early boot menu and switch to NTSC by pressing the space key once, and see if you get a picture.
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I also have an A1200 wich my Ez Scandoubler wont work in, it works perfect in my A4000 (for years) but wont work in the A1200..
Maybe it is the power as CLS mentions?
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I bet that your VGA monitor has trouble with low refresh rates and cannot cope with anything below 31hz, which is needed for PAL. If you were to switch to NTSC, it would probably work as NTSC scan-doubled is slightly above 31hz and pal is closer to 30hz.
I thought that this might be the problem but I tested it with two monitors, one is my syncmaster 940BF which is supposed to be able to handle at least 60hz, and the other one is an old 15" AST and it says 60/50 hz on the back. And switching to NTSC doesn´t help either...
Btw. my mobo revsion is 2B, is this known to be a troublesome revsion? Because I feel like I´ve always had problems with this crappy mobo :-(
But take a closer look to your mobo rev, and go to aminet in the hack directory to find the modification to get the missing power ;)
I can´t find any hack for this revision in aminet, do you know the name of it?
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i have the same mobo and it works fine all these years. i have test it with this scandoubler and it's ok. your problem is somewhere else.
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There is another possibility as well. The A1200 dosent have a large power supply and has been known to cause problems with the Scandoubler because it draws to much power to work properly.
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hi,
now i'm using a TVBox7 from Avermedia to send composite video signal to a VGA monitor. But it's a poor quality mode and i'm thinking to buy an indivision flickerfixer-scandoubler.
LG1915S can display signals from 30Khz-83Khz horizontal and 56Khz-75Khz... some problems with this especifications and the scandoubler solution? :-?
a1200, blizzar 1230-iv with 8Mb, hd 2'5. i'll need a better power supply soon... but it will be suficient with an a500 power supply? (with and without the scandoubler)
bye!
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a500 psu is not enough with the hardware you already have pluged...
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There is another possibility as well. The A1200 dosent have a large power supply and has been known to cause problems with the Scandoubler because it draws to much power to work properly.
My power supply's output is 200W. Not so much, so I tried to remove the blizzard. No difference though, next I´ll be trying to disconnect some drives as well.
btw, the scandoubler gets warm after a while, so I guess it gets some power, but perhaps not enough?
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can you conect the amiga with a normat 23pin cable to somwhere else, tv set for example with scart, to test if the amiga's rgb output is ok?
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ok i see you already have write about it.
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neuroflip wrote:
LG1915S can display signals from 30Khz-83Khz horizontal and 56Khz-75Khz... some problems with this especifications and the scandoubler solution? :-?
bye!
Yes. PAL is 50Hz Vsync, which is below the range you mention (56Hz-75Hz Vsync). So it will not work with the monitor you have.
A different option is to buy a monitor with a SCART input (VGA monitor/TV combination), and simply use a Amiga->SCART cable. Works great.
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"the scandoubler gets warm after a while, so I guess it gets some power, but perhaps not enough"
Yes it does get warm I actualy drilled several holes in the plastic cover to alow for the heat to dissapate faster. I have seen some people who have added a small fan to it.
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how do you power up your amiga? the amiga rgb port (http://www.ntrautanen.fi/computers/hardware/misc/amiga_rgb.htm) gives -5 volt at pin 21. is your psu gives this voltage to the amiga? are you using a proper amiga psu or something from pc world? maybe the scandoubler needs that -5 volts.
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Yes. PAL is 50Hz Vsync, which is below the range you mention (56Hz-75Hz Vsync). So it will not work with the monitor you have.
My specs for my monitor says it has scanning frequency of 30-81kHz horizontal and 56-75Hz vertical (flascreen monitor syncmaster 930bf). And the backside of my other two monitors says 50/60Hz. Does this mean that none of these monitors will work with the Indivision scandoubler??
If so, can anyone recommend a somewhat new flatscreen monitor that will actually work with the Indivision?
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i think that the other 2 maybe can work with it. i test mine on my proview 17 flat monitor (30-98khz 50-160hz). it's fine.
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amije wrote:
i have the same mobo and it works fine all these years. i have test it with this scandoubler and it's ok. your problem is somewhere else.
You can't make such an easy conclusion! I have a MV1200 scandoubler, which works fine on my rev. 1D1 motherboard installed in my A1200 tower, but it doesn't work with the same rev. motherboard in my A1200 desktop.
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you are talking about a diferent scandoubler. i and SuperTurbo talking about the same scoundoubler which (mine) Matthew at amigakit test it at his a1200 too.
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I am fully aware of that. Even though it's the same scandoubler the two of you have, it doesn't mean that it will work on no matter which rev. 2B motherboard out there you use it on.
The same with my scandoubler; it works on one of my motherboards, but not on the other, even though they are the same rev. I'm not expecting it to work with all rev. 1D1 motherboard either.
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you are absolutly right but meanwhile and so far we (all here) adding some thoughts/ideas in progress based on the facts, trying to solve this issue. of course as you can understand some of them are faults hopping someone finaly will hit the right answear :-)
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You think this scandoubler is evil ?
I have an A1200 accelerator that works perfectly in an A1200 (3.0 kickstart) but refuses to activate its own RAM (or goes to pink screen) under Kickstart 3.1
3.0 workies fine
3.1 does not work.
Go figure.
I call it, Amiga's with attitude.
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:laughing:
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@whiteb:
Might it perhaps be this (http://amiga.resource.cx/exp/search.pl?product=cobra&company=dkb) card? (read bottom line of the notes)
/Patrik
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Hi SuperTurbo,
I bought an Indivision sd/ff from Amigakit this past February for a 4000 I got off ebay in January. When I first hooked it up the screen was extremely jittery, so I adjusted the potentiometer slightly and the screen immediately went black. No amount of adjusting made any difference at that point, so I thought the unit was faulty.
I kept trying to adjust the potentiometer in hopes of bringing back the picture, but no amount of adjustment seemed to make any difference. In the process I was leaving the Amiga on for longer periods of time (30 minutes or more), and eventually I saw a picture - albeit a very jittery one. Each time I turned on the computer the screen would be black for several minutes, but then would show a jittery picture which would settle down the longer the machine was on. Over the next couple of days this transitioned to starting with a jittery picture rather than a black screen, and ultimately to a rock solid display from the moment I powered up.
I'm not sure what caused this strange behavior, but hopefully something as simple as leaving your machine on for a while will help like it did for me. Good luck!