Imac mid 2011 - External monitor / Thunderbolt port

[PeteMacMan]

HI - I have a Mid 2011 Imac which I've attempted to connect to a 1080p HD Samsung Tv for a second monitor.

I purchased a Thunderbolt adaptor that links to an HDMI cable and connected with that method.

So stage 1 all good Mac recognises the Samsung, brings up the relevant settings for screen display asks if you want to mirror or not, etc.

BUT

There is no display showing on the Samsung - cannot work it out for the life of me why when the mac recognises the extended screen no actual image is showing. I've switched the tv to the correct HDMI connection (have tried all four HDMI ports) yet.. none show. Set to mirroring so ensure there should be a full image shown. nothing.

Anyone any ideas?

thanks
Pete

 

[TheShortTimer]

HI - I have a Mid 2011 Imac which I've attempted to connect to a 1080p HD Samsung Tv for a second monitor.

I purchased a Thunderbolt adaptor that links to an HDMI cable and connected with that method.

So stage 1 all good Mac recognises the Samsung, brings up the relevant settings for screen display asks if you want to mirror or not, etc.

BUT

There is no display showing on the Samsung - cannot work it out for the life of me why when the mac recognises the extended screen no actual image is showing. I've switched the tv to the correct HDMI connection (have tried all four HDMI ports) yet.. none show. Set to mirroring so ensure there should be a full image shown. nothing.

Anyone any ideas?

thanks
Pete

Do you have another TV that you can test the cable with?

 

[PeteMacMan]

Do you have another TV that you can test the cable with?

Frustratingly 3.. All 32 inches plus it seems the blocker is a limitation of of an external display max being 30 inches!? The graphics card being the limiting factor..

New cable coming today just to confirm that fact is truer than true alas..

 

[Nguyen Duc Hieu]

Frustratingly 3.. All 32 inches plus it seems the blocker is a limitation of of an external display max being 30 inches!? The graphics card being the limiting factor..

New cable coming today just to confirm that fact is truer than true alas..

Unplug, replug the HDMI side (turn-off the TV while doing) to see if it can fix the issue.
My TV got "no signal" displayed all the time, especially when the PC wakes up from a long sleep. Reseting the PC (Windows) fixed my problem.

 

[PeteMacMan]

I did do all that... it seemes ultra cheap cable wasnt the way to go..

But good news..

Whilst the 30 inch max output is spelled out repeatedly by apple - Ive now tested on two new cables £6.50 each and .. it works - 32inch full display ahd at full resolution 1080p, not tried 4k Yet, but great start!

 

[PeteMacMan]

Works on 65 inch also... At 1080p but the adaptor I purchased is 1080p only there is a 4k veriosion so. May try that also?

But all working

 

[Nguyen Duc Hieu]

Works on 65 inch also... At 1080p but the adaptor I purchased is 1080p only there is a 4k veriosion so. May try that also?

But all working

I don't think there is enough bandwidth in the Thunderbolt 1 port to output 4k video.
The thunderbolt 1 to HDMI adapter, or miniDP to HDMI adapter may not support HDMI 1.4, minimum requirement for 4k @24fps transmission.

 

[PeteMacMan]

Well this gets stranger and stranger.

Adaptor 1 1080p max
- The hdmi adaptor that's 1080p only lives up to its rep. Top output from TB Is 1080p feeding into a 4k 65 inch TV
- but gives me an option to underscan (shrink useable screen space within the overall 65 inches of TV
- and to change refresh rate from 60hz or less.

Adaptor 2 4k max
- The hdmi adaptor that can transmit 4k...first try, did only 1080p also 1920 x 1080 and gave me no 9ther options, underscan or to alter htz.
- I then unplugged and switched back to Adaptor 1, I then switched again back to adaptor 2 and suddenly a whole load of new resolution options came up (some stating low. Resolution next to them) but with real High pixel density. (see picture)
-highest low res is 4096 x 2160 (higher thelan 4k)
- highest full res is 3840 x 2160 (4k) very little diff in quality to the above but screen fit is perfrct (4096 sent image off screen very slightly )

So the AMD RADEON HD 6770M 512 MB can transmit 4k it seems.. and more...

Did notice when in 1080p 60hz was useable but the 4k and higher maxed out at 30hz. (someone might be able to explain this to me and the impact or why)

But.. All a images picture sharp.

This Mac just keeps Giving