I've been reading a lot of TV Tropes and got some free time so decided to cover some tropes (common writing themes used in popular culture) in Power Rangers. Since Power Rangers been running for almost 25 years and Sentai for 42, lots of plots have been reused. I will be covering Sentai later as there is a lot more series to go through. I decided I won't do big tropes that were done less than twice like evil sisters (Astronema and Tenaya) or evil turning good.
MMPR (1993) - Season One
In the Turtleshock episode, he freezes Billy, Kim and Zack but no ice involved.
Goatan freezes the original Megazord.
MMPR (1994) - Season Two
Jason, Trini and Zack are frozen in the Ninja Encounter 3-parter,
Kim, Tommy and Rocky almost freeze un-morphed in Storybook Rangers.
Lightspeed Rescue (2000)
Angela Fairweather is frozen by a monster.
Dino SuperCharge (2016)
Some of the Rangers are frozen in large blocks of ice un-morphed. Also Tyler and Shelby in the first episode but briefly.
Let me know if I missed some.