27" Thunderbolt Display now turns offs after a while.

It surprised me but these setting changes appear to work.

On both my systems with Thunderbolt Dispays the display easily turns on after it going sleep (or at lest turning of the display itself). So far so good. Thank you.

The two 27” Thunderbolt displays have two integrated cables. One is for AC power and the second has a data/power cable with a thunderbolt connector and a mag connector to power a laptop. These cables do not look frayed in any way.

Once power is applied the computer boots and the display works. Eventually the display “sleeps” and can no longer be “woken up”. If power is cycled it can be restarted. I’m using one connected to a 2014 Mac Mini and the second to a 27” iMac 2019 with quad i9 processors.

have not changed the settings yet on the iMac one because the display is no longer “accessible” since it went to sleep and the iMac is still in the middle of a large data transfer.

two follow up questions. One, how do you get a replacement for the Octopus cable? Any link you can provide?

Two. Is there a real diagnostic you can run to test the cable to know it its really bad or just appears that way?

Found out so far that changing the Energy savings settings appears to resolve the problem so far on both my systems with 27" Thunderbolt Displays so away of testing them with a diagnostic would be helpfull. Thank you and take care.