Originally Posted by lincolnjkc

I believe the PSU change from lights to placards being done as part of the interior retrofits and new aircraft delivery -- a recent PremPlus 772 and 787-10 both had this style indication.

Given that the no smoking sign hasn't been turned off in +/-30 years I'm surprised it's taken this long to realize the savings in maintenance, weight, electricity, heat dissipation [may not actually be a problem in flight], idiot conflict when lamp burns out ("but the sign above my seat was off! I thought it was OK to light up!"), etc.