Home Forums Hardware Mac Desktops & Notebooks imac + minidvi/dvi adap + apple display incompat?

I am pulling my hair out here trying to fix an imac that refuses to send video to an external dvi display. It's a fairly new black/silver imac with the mini dvi port, and am trying to hook it to either a 23 or 30" apple display (silver) via an apple dvi to mini dvi adapter.

After swapping out logic board, video card, and BOTH, I pulled another imac off the shelf and tried it, with a different adapter, on a different display, and STILL got no video.

I know with projectors etc you sometimes have to hook things up in a certain order because the mac will see the adapter when you plug it in and will look for the display, and if you hook the adapter to the computer before the adapter to the projector, the mac doesn't see any display and gives up, and you get nothing when you plug in the projector.

I am wondering if this is a double gotcha, because the display is also acting like it's detecting when the adapter is plugged in. Is this a case of the computer has to be plugged into the adapter before the adapter is plugged into the display, AND the display has to be plugged into the adapter before the computer is plugged into the adapter? (catch-22)

We've made several attempts to plug the adapter in at both ends at the same time but it doesn't seem to matter.

I've never seen a silver apple display hooked to an imac via a mini dvi adapter before so I can't say for certain that I know it works, but I can see where there may be an incompatibility. Everyone else I've seen using an external display on an imac using the mini dvi port has been using a non apple display or a VGA display. (vga works fine!)

I'm a bit out of my depth here, but I would ask if you have tried plugging in the adapter and the external display and powering it on before turning on the iMac.

The reason I ask is that my only experience using an external projector with my PowerBook G4 required that sequence of events. If the Powerbook was on before the projector, no amount of fiddling with system prefs or plugging and unplugging would get it to recognize the external device.

Yep I've been trying all sorts of variations on that. The solution you are using is to humor the computer which is why you have to do it in that order.

The problem I am suspecting is that BOTH the computer AND the display are needing to be humored in this way, and as a result you can't satisfy both of them at the same time. (you cannot plug in A before B, -and- B before A, at the same time)

I realize this does not solve your problem, but at least it provides more information for you to go on. I have an older 15" Apple display connected to my 24" 3.0.6GHz Core 2 Duo iMac via a mini dvi to dvi adaptor connected to a dvi to ADC adaptor which in turn is connected to the monitor. This lashup has been very reliable and is completely without any startup quirks or "whose on first" issues.

You said you tried another iMac, another cable, and another monitor. Was the other monitor also a 23" or 30". If so have you tried a smaller monitor just as a test?

not sure what customer was using. I tried a 30 and a 23 aluminum