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Diggory Laycock · Mar 20, 2006, 07:25 AM

Hi,

I've got an old cube which has ADC video out (and VGA).

It's currently connected to a tiny old CRT - but I'd like to connect it to my TV.

I bought an ADC to DVI cable and a DVI to HDMI cable - and connected them all together to the HDTV via the HDMI socket - However - nothing appears onscreen.

Am I missing something? Is this not a valid way of chaining these video signals together?

Maflynn · Mar 20, 2006, 08:00 AM

The video card is probably not strong enough to drive the TV. For instance I have a 20" Apple Cinema Display. The stock video card from the Cube wasn't powerful enogh to display anything it no picture appeared.

Diggory Laycock · Mar 20, 2006, 08:16 AM

hmmm - even when I set the resolution really low? or do you mean electrical power...?

Maflynn · Mar 20, 2006, 08:40 AM

I'm not sure to be totally honest, all I do know is that the stock video card is pretty weak by todays standards and even the video card replacements that are cube compatible are considered anemic.

If I were to hazard a guess it would be the electrical output required to drive the monitor. A lot of the Cube's ports are underpowered, such as the usb ports so I'm hazarding a guess that could be the issue with the video card.

tooki · Mar 20, 2006, 07:11 PM

That is complete nonsense. Bus power and signaling voltage are entirelty separate, unrelated things. Modern graphics cards differ in their ability to render graphics, not output voltages.

Furthermore, ONLY ADC displays were powered by the computer. Any TV or display with a VGA or DVI (or HDMI) input must provide its own power.

More likely, a) the double-adapting is dropping a sense pin needed by the TV, b) the TV doesn't like input that doesn't include copy protection, or c) the default video mode isn't one the TV supports.

tooki

Diggory Laycock · 06:12 AM

Thanks for the clarification Tooki - I don't think it's an HDCP copy-protection problem, since I've hooked-up my Powerbook to the same TV via DVI->HDMI.

I don't think the TV minds about specific resolutions either - I just hooked it up as the second display on my PB at a range of resolutions - and it displayed them all without fuss.

In so far as pins go - here's a photo (bottom plug is the ADC -> DVI cable. Top is the DVI-> HDMI cable.)

Sorry about the blurriness, my camera phone appears not to like focusing on close-up objects...

http://www.interfacebus.com/Design_C...e_DVI_Bus.html

It seems that the following pins are not there:

C1-C4, 4,5, 12,13, 20,21

I suppose that makes it 'Single Link DVI-D'

tooki · Mar 21, 2006, 03:47 PM

Exactly right! The top is a single-link DVI-D connector. Most adapters have holes for the dual-link pins just in case you are using a dual-link cable, even though ADC is single-link only.

tooki

joe · Mar 21, 2006, 06:09 PM

Just curious - is the VGA cable completely disconnected from your Cube graphics card when you try to connect to your TV? IIRC, some Cube graphics cards support using only 1 port at a time - either VGA or ADC but not both.

Diggory Laycock · Mar 21, 2006, 06:46 PM

Yes - when I tried it it was just the ADC adaptor connected, no VGA at all.

Perhaps the cube thinks that nothing is connected...