Thunderbolt display output distorted

Question

Working on MBP 2.4 Ghz, i5, 8GB
OSX 10.9.4
When connecting via DisplayPort-cable to my Thunderbolt port towards a external TV (Philips 40") I see a nice mirrored image(see image 2).
However, after some time (random) I receive a distorted image on my mirrored TV (see image 1).
After disconnecting the cable and connecting it again, it restores the mirrored image back to the correct version. After a certain time (random) it swapped back to the distorted image..
Any suggestions?, tried reset of PRAM, ... nothing seemed to work.
Many thanks !

Answer 1

Hello there, Florinello17.
The following Knowledge Base article offers up some great, in-depth steps for troubleshooting your issue:
Apple computers: Troubleshooting issues with video on internal or external displays
http://support.apple.com/kb/ht1573
No video or no signal, image distortion, "snow," or flickering
Check connections
When using an external display be sure to check the following:
If you're using an Apple notebook, confirm the AC power cable or adapter is securely connected to the computer and the cable providing power to the display is also secure. It is always good to have your notebook connected to AC power when an external display is in use.
Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display. Refer to these articles to assist you with adapter compatibility and further configuration information:
Monitor and Display Adapter Table
About Mini DisplayPort to HDMI adapters
Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)
Thunderbolt ports and displays: Frequently asked questions (FAQ)
Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.
Try unplugging the video adapter or cable and then plug it back in.
If more than one video adapter is in use (or "daisy-chained"), troubleshoot by using only one adapter.
Example: A mini DisplayPort to DVI adapter connected to a DVI to HDMI adapter is an unsupported configuration because there is a series of adapters in use.
If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).
Reset the system
You can reset the Mac's parameter RAM and SMC.Reset the resolutionStart by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:
Start up in Safe Mode.
From the Apple () menu, choose System Preferences.
Choose Displays from the View menu to open the preferences pane.
Select any resolution and refresh rate that your display supports.
Restart your computer.
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.