@XianLi: what is the approx value of the resistor that you've used?
The dock only supports sound jack, as there are only 2 terminals in the jack port.
however my guess is that the Iphone standard dock can be modded to support video out on the old cables....

I've used several values:

1KΩ, 5KΩ, 10KΩ, 100KΩ, 1MΩ.

Like i said before, if someone can probe the resistance value between the pin 10 and the ground, it would be easier.

Anyway, i've got to buy an iPhone-iTouch dock next week for a friend, so i will open it and check it, if no one has posted the values before.

Well I finally conceded to going out and buying a universal dock.
As I still can't figure out how to nondestructively open one up, I probed with my meter across the "accessory Indicator" pin (10) and common ground (29) and got 570K
(+/- 5K) the closest resistor I had in my kit is a .5M which I tried in combination with a few other lower values to try and get the iPhone to acknowledge my hotwired old firewire cable as an accessory.
I did get it to come up with "This accessory is not compatible with iPhone, do you wish to activate Airplane mode to avoid etc etc"
I still couldn't get any composite video out of pin 23!?
More bad news, the dock tells the iPhone when there is an AV lead plugged into the line out jack as the sound diverts from the phones internal speakers, whether this changes the accessory indicator resistor value I am yet to determine.
Also, i still can't video out of the Universal dock using a normal AV lead, left and right audio yes, and yes the lead orientation is changed, but still no video.
The "resistor in the AV lead theory" is starting to make more sense. Anyone got one and a multimeter?


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@freeproductions: The dock is both snapped and bonded. I opened mine by unsnapping the plastic using a small scredriwer and toothpick used as wedges. haha..
The wedges eventually overcomes the bondingtape inside. HOWEVER: the dock is not nice and neat anymore. When it stands on the table you cant tell the difference but on the underside its filled with scraping marks.
I was earlier tempted to mod the dock, but having though about the work involved in this, im going with fixing the cable instead.
I am testing a variable resistor setup on my test board wqithin hours. Will check back with any usable values.

Rutonium:
Thanks for all of that, I actually edited my query out of my post because I figured out how to open the new dock, a lot easier with the Universal dock (no glue)
I am trying to post a picture of the inside of it however my upload keeps failing!?!
The Universal dock also only has two rails connected to the AV jack, however does claim to offer video out in the manual, very confusing!?!
There is definitely something in that Apple lead!
Let us know what happens with your experiment with a pot.

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I would just like to add my support for the sterling effort you guys are putting in to cracking the INSANE methods Apple has gone through to lock third-party vendors out of making video-out cables for the iPhone.

Personally, I think it is a complete home-goal for Apple to do something as near-sighted as this. So many people I've spoken to have said that one major factors in buying an iPod/iPhone is the wealth of accessories available for it, compared to other devices.

So what Apple have done in making sure that £35 goes their way instead of the way of the third-party developers is to actually both limit the flexibility of the device in the eyes of the public, and to serious piss off people like us who are in the know and would only buy an iPhone if we were assured we could have it on our terms (third-party apps, any network, etc...).

To all you pioneers out there that are wrestling control of our devices back from Apple, I salute you. Keep up the good work.

Sorry guys, bad news.
I´m unable to get the iphone to accept my attemps with resistors.
Tried various pins and various resistors. I'm really frustrated with this, so much that i've now ordered the original cable. Should be here tomorroww.
I'll see if I can make a couple of x-ray images of it before i take it apart. (im an engineer, not a doctor ;-) )

I'm pretty sure the new Apple Video Cable (dock plug to rca/cinch) has something to do with the video out activation.

XianLi:
Hey, how did you get your iPhone/Touch to display that "Display on TV?" ?
Does anyone have an Apple video cable so we can get to the bottom of this?

Also; why can't I attach an image to a post? Thanks guys.

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hey guys... i've seen a belkin/griffin "ipod video cable" which is a 3.5" triple layer (i hope that's the term in english - it means audio and video) at one end and 3 RCA at the other. it is ment for video ipods... any chance such thing would work?
i'm sorry if the question is a noob question - if it is just say so and i'll get the point...