Cyberlight 2.0

Power is the most likely culprit.
What voltage are you running at? Generator power or venue service?
I did a tour earlier this year with 18 Cyber 2.0 and didn't really have any issues.
What firmware version are your units? v1.2.7 is the latest.

Hope this helps. :)

What console are you using? What is your procedure for striking the lamps? Does it really take "hours" or is it just a couple of additional strike commands?

I'm using a Grandma not with the latest software but since it's a timecode show thats been running for more then a year I will not update the software in the desk.

For hours is a bit on the long side, but it sometimes take's more than
10 lamp-on commands for resets hard and soft.

I always reset the entire rig before I strike all fixture's.
Then I select all cybers from a pallet after that I give 'em a lamp-on. (So the scans are directly in the programmer)
The programmer of the show build a special cue for it but thats even worse to use.
It's always a couple of Cyberlights that won't strike but never the same.

I've already ruled out dmx connections and bad power.
Power is always a mains (powerlock) from the venue and my rack's have a build in measuring/failure system, they won't switch on at bad power.

The Cyber 2.0s should strike upon power up if DMX is present.

If they have been given a "Shutdown" command and then given a "Reset"
later the lamps should strike during the Homing process. You should not need to then give a "Lamp On" command after that unless the unit did not strike for some reason.

When striking so many units at the same time you may be causing a temporary voltage dip due to electrical in-rush. Especially since these fixtures draw considerably more power than your average moving light.

Try resetting the units in smaller groups or even individually rather than all at the same time to avoid this.

Hope this helps. :)