Continuity mistake: Up until Green No More in Series 2 (where the Green Ranger powers are destroyed), the Green Ranger's overshield constantly changes between solid-looking metal to flimsy-looking cotton. This is the most obvious difference between the Japanese and US footage.
Other mistake: In the scene where Tommy is proving himself to Goldar on the beach against the putties, Tommy stares down the last remaining putty and makes a charge towards him. In the wide shot of Tommy charging towards the putty, one of the "dead" putties on the ground lifts his head off the ground slightly, almost as if he is watching the action unfold.
Plot hole: In this Episode Globbers energy is drained when Alpha stops the Solar Eclipse, and his Energy drains in the sunlight and severed the physical link between him and Ninjor. Despite the fact in the previous episode Globber had no trouble fighting in the sunlight, and the link stayed intact in the sunlight.
Other mistake: Episode 13-12: "Shadow (2)." When Cruger is challenged to defeat 100 robots, a red countdown meter appears on the screen, ticking down each time Cruger dispatches an opponent. When the counter is at 21, Cruger slices his sword at a robot, which then goes down. But the counter stays at 21 and only goes to 22 when he slices at the next robot. Every robot in the sequence goes down after a single hit from Cruger's sword.
Continuity mistake: This can only be seen for a few frames, so slow motion may be needed. Tommy reveals himself as the White Ranger by unclipping his helmet; however, his ponytail is already visible. Tommy's hair should have been inside his suit/helmet if he had just unclipped it. From behind shots, it is tucked in.
Revealing mistake: The Putties, which Zedd and Rita use as cannon fodder for the Rangers, are made out of clay. When they are hit, chalk appears, to signal that they are being "worn down". When played in slow motion, we see that the chalk is on the Ranger's feet, before they hit the Putties. This is particularly true in closeups.