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Faulty amiga video port - advice please

Posted: Tue Feb 15, 2011 7:49 pm
by gdh82
The floodflight failure I've been having is in fact a problem with the video port on my A600. We discovered at our last tournament that same problem occurs even with a different cable and monitor. The port itself isn't lose or anything and shows no sign of damage.

Any ideas on if this is fixable? Alternatively I have an 'scrap' A500 which I've been using for spares (already missing a keyboard) and was wondering if the video port could in theory be transferred to the A600? Any advice appreciated.....

Re: Faulty amiga video port - advice please

Posted: Wed Feb 16, 2011 7:17 pm
by Steve Camber
Have you tried both the standard video port AND the composite video port (yellow circle)?

Re: Faulty amiga video port - advice please

Posted: Wed Feb 16, 2011 9:33 pm
by gdh82
Thanks Steve. We hadn't tried both at the same time but unfortunately it produces the same result. With the monitor (Commodore 1084ST) switched to RGB it's the same 'floodlight failure' and when I move the switch to CVBS/LCA it produces the B&W image?

Re: Faulty amiga video port - advice please

Posted: Thu Feb 17, 2011 2:23 pm
by Steve Camber
Does the black and white image appear to show the floodlight failure too? Or is it just standard KO2 in black and white?

Black and white while using a yellow composite video source tends to suggest a NTSC/PAL mismatch. Can you use the "two mouse buttons on boot" trick to switch PAL/NTSC (or is that just A1200) ?

Re: Faulty amiga video port - advice please

Posted: Fri Feb 18, 2011 12:18 pm
by gdh82
That's right Steve, the B&W picture purely lacks colour and is quite different to the floodflight failure (which no longer flickers incidentally - it's just dark!). Was out all last night but will try the mouse button trick later and let you know. Thanks again.

Re: Faulty amiga video port - advice please

Posted: Fri Feb 18, 2011 12:50 pm
by Steve Camber
Well that's a good sign. I'm guessing it's just a problem with the video port of your amiga instead of a problem deeper within the amiga internals. One thing to note. Never connect/disconnect anything to the video port while the amiga is on. It's ok with the yellow composite connector though.
Also, try connecting to a TV instead of your amiga monitor.

Re: Faulty amiga video port - advice please

Posted: Fri Feb 18, 2011 9:12 pm
by gdh82
Definitely good news that the composite output is perfect. 8) So it seems to confirm the RGB port is the problem.

I tried the double mouse button press on bootup and although it seems to delay the start-up (until buttons released), it doesn't appear to change the display modes (i.e still B&W via RGB). This impressive A1200 FAQ describes "the 'double' video modes of the A1200's AGA chipset" which maybe explains why at the 8-Bit tourney, Steve was able to wire his A1200 to his monitor via the composite output? I've also read elsewhere how 'unrepairable' A600s are, and were apparently described as "a complete and utter screw-up" by Commodore's MD (UK)! :lol: :lol:

I'm grateful for all the help Steve but beginning to think I should just stick with what I've got. Just had a play with the kit design and even found two colours that show up with the floodlights off! A black pitch is suddenly surprisingly cool! :)