iMac 27" to TV HELP!!

I have an iMac 27" with the mini DisplayPort HDMI cable connected to my LG Plasma and it doesn't work.

Now i have tried with my brothers smaller intel iMac and it works fine. It actually picks up the signal right away when it's plugged into the tv and works. Did Apple change something on the 27"..? Am i doing something wrong?

Can someone help plz.....

nickr1 said:

I have an iMac 27" with the mini DisplayPort HDMI cable connected to my LG Plasma and it doesn't work.

Now i have tried with my brothers smaller intel iMac and it works fine. It actually picks up the signal right away when it's plugged into the tv and works. Did Apple change something on the 27"..? Am i doing something wrong?

Can someone help plz.....

Click to expand...

That port on the iMac is for incoming video… to use the iMac as a display for another device, like a laptop or even a Blu-Ray player. You cannot use it to send video out.


EDIT: I had a link, but that was talking about something else. I'll double check this.

Second edit: Ok… here's that link:
AppleInsider | Tests confirm Apple's 27" iMac only supports DisplayPort input

The problem here is that for some reason, on the 27" iMac, the DisplayPort only works with other DisplayPorts. Using an HDMI adapter won't cut it.

lifesabeach: I think that article is titled a little 'mis-leadingly' (made-up-word ?). I think it refers to the the displayport only taking displayport signals for input, not that it can only do input not output.... if you see what I mean.

The iMac 27" mini-display port is two-way:
Apple (United Kingdom) - iMac - Technical Specifications

# Mini DisplayPort output with support for DVI, VGA and dual-link DVI (adapters sold separately); 27-inch models also support input from external DisplayPort sources (adapters sold separately)
# Support for extended desktop and video mirroring modes
# Simultaneously supports full native resolution on the built-in display and up to a 30-inch display (2560x1600 pixels) on an external display

Click to expand...

You'll need a cable like this:
For only $27.81 each when QTY 50+ purchased - Mini Displayport Male and USB Male Audio to HDMI Female Converting Adapter | Mini DisplayPort to HDMI / DVI / VGA Adapters (uses the USB for audio)
or this
Mini DisplayPort to DVI Adapter - Apple Store (U.S.)

mrplow said:

lifesabeach: I think that article is titled a little 'mis-leadingly' (made-up-word ?). I think it refers to the the displayport only taking displayport signals for input, not that it can only do input not output.... if you see what I mean.

Click to expand...

According to the article I linked:

According to Apple's stated specifications however, the 27" iMac's video input feature will only ever work with DisplayPort devices, and no physical adapter will change that fact.

Click to expand...

That article was written in 2009, before the current gen of iMacs came out, which is what Apple's product page is certainly referring to. Assuming the article was correct, then it seems they changed the specs for the latest gen.

Nickr1… can you confirm which specific model of iMac you have?

EDIT: I just noticed that the article was talking more about video in. This may not apply to outgoing video. Will have to double check on all this. Hmmmm….

According to Apple's stated specifications however, the 27" iMac's video input feature will only ever work with DisplayPort devices, and no physical adapter will change that fact.

Click to expand...

That's what I was trying to say....... but badly I think.... the "input feature will only ever work with DisplayPort devices" - that doesn't preclude output....

The input only accepts DisplayPort signals, hence products like the Kanex HD which take HDMI signals and process them to DisplayPort signals.
But the output is more flexible and works pretty much like the displayport on a Macbook etc.

I have the 2009 27" i7 iMac and the DisplayPort out works fine with the Apple DisplayPort to DVI adapter. The same one that works on my Alu unibody MacBook

mrplow said:

That's what I was trying to say....... but badly I think.... the "input feature will only ever work with DisplayPort devices" - that doesn't preclude output....

The input only accepts DisplayPort signals, hence products like the Kanex HD which take HDMI signals and process them to DisplayPort signals.
But the output is more flexible and works pretty much like the displayport on a Macbook etc.

I have the 2009 27" i7 iMac and the DisplayPort out works fine with the Apple DisplayPort to DVI adapter. The same one that works on my Alu unibody MacBook

Click to expand...

Ah. Uhhhh.. I think I sorta got it. Are you saying there are two types of adapters... one that does a straight HDMI-to-DP, and another that goes an extra step to "fake" being an actual DP device? If that's the case, then the OP may have the wrong kind? He obviously must be using something...

Back to nick... can you confirm what cable you have?

Here are the Graphics & Video Support Tech Specs for the current 27" iMac Model. DVI Support is about 3/4s of the way down.

Hope this helps
DavidH

Graphics and video support

27-inch model with dual-core processor:
ATI Radeon HD 5670 graphics processor with 512MB of GDDR3 memory
ATI Radeon HD 5750 graphics processor with 1GB of GDDR5 memory
27-inch model with quad-core processor:
ATI Radeon HD 5750 graphics processor with 1GB of GDDR5 memory
iSight camera
Mini DisplayPort output port with support for DVI, VGA, and dual-link DVI (adapters sold separately); 27-inch models also support input from external DisplayPort sources (adapters sold separately)
Support for extended desktop and video mirroring modes
Simultaneously supports full native resolution on the built-in display and up to a 30-inch external display (2560 by 1600 pixels)