Apple II+ Composite Video issue

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Apple II+ Composite Video issue

Hello, 

I have an Apple II+ with Video sync issues, 

Using a standard Apple composite monitor, I had vertical sync issues, and I changed a few ICs to fix it : 74LS161 x2 at D11 and D12, 74LS32 at C13 and 74LS32 at C14. 

Now the image is stable with the classic monitor. 

However when I use a Retrotink 2x pro, I do not get any sync (black screen). Using another Apple IIe I succeed with the retrotink. 

Is there any good document explaining step by step  to troubleshoot the apple II video sygnal using an Oscilloscope?

Where to start with ?

Thanks

Vincent

 

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I've run into several NTSC ->

I've run into several NTSC -> HDMI converters which work fine with a //e or IIgs but produce very poor results or no picture at all from a ][+ or clone and ever more that won't sync right to a Videx type 80 column card even though they work fine with 80 column output from a //e or IIgs.

 

Apple did some things with the //e which improved its compatibility with a lot of NTSC devices which I'm not sure can easily be retrofitted to a ][+.

 

 

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Interested to hear what you

Interested to hear what you find. My XRGB2+ Scaler has issues with IIe composite only in monochrome text, graphics work. I never went as far as trying to clean up the signal in the Apple IIs, it's really the same with this scaler across all my IIe and II+ systems as far as I remember. 

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Ok thanks for the feedback, I

Ok thanks for the feedback, 

I will stop to fight to get this ‹orking ;)

Vincent

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You might consider an A2VGA

You might consider an A2VGA card or try a diferent NTSC->HDMI adapter.  As I said, I've had different results with different ones.

 

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