Scandoubler problem

[SuperTurbo]

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.

[CLS2086]

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

[x56h34]

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.

[krize]

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?

[SuperTurbo]

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?

[amigagr]

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.

[tonyvdb]

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.

[neuroflip]

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!

[amigagr]

a500 psu is not enough with the hardware you already have pluged...

[SuperTurbo]

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?

[amigagr]

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?


-edit-
ok i see you already have write about it.

[PaSha]

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.

[tonyvdb]

"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.

[amigagr]

how do you power up your amiga? the amiga rgb port 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.

[SuperTurbo]

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?