Originally Posted by Raistlin_HT
... is there a 'best practice' in terms of what order to power up devices when a Darblet is in the signal chain? I am using a Harmony, and routinely have HDMI handshake issues when turning on my system. It seems the Darbie is the culprit. My work around is to manually switch to another HDMI input on my DVDO Edge once everything has been up and running for a bit, then switch back to my main source. Usually after that I'm good ...
Bachelor is right, powering on devices starting with the display, and then working backwards until you reach your source, gives you the best chance to successfully complete EDID handshakes at each step.
You can also use your Harmony to incorporate delays into each step in the power on sequence, thus giving additional time for each device to be fully operational, and maximizing the chance of correctly completing each set of handshakes.
The other advice routinely offered for Darblet users with handshake issues includes (1) checking for a snug, clean fit on each HDMI connection, (2) using only high speed HDMI cables, (3) using Redmere cables for HDMI runs longer than six feet, (4) avoiding stand-alone switches and splitters, (5) turning off Deep Color settings on all devices, and (6) setting all devices to explicit input and output settings, rather than relying on "auto" settings.
Additionally, some users have reported success by changing *where* in the chain the Darblet is placed. It is most often placed directly after source; however, some users have reported good handshake performance only after placing the Darblet at the end of their chain, immediately before the display.
No doubt aaronWT accurately reports his experience with dozens of devices and cascaded HDMI switches, but his experience is as atypical as it is fortunate. Each combination of equipment behaves differently, and users with relatively simple set-ups can still experience handshake issues, as you have. For them, it takes a little effort to achieve a stable video chain ... which is precisely why you asked.
Fortunately, the Darblet is worth the effort. Hope that helps. Good luck!