Here's new footage of Shockatron while in the Skull Cavern. All of his shots in the Skull Cavern had to be reshot due to Diabolico being in them. Shockatron was 1 of Diabolico's monsters.
Here's more new footage of Shockatron
This shot of Shockatron is when it goes to Sentai footage for the first time in this episode.
Electricity is added to the effect of Shockatron's power in order to make it seem like he's actually draining the electricity in the Power Plant.
Here is new footage of the 6 Rangers, the primary ones riding their Cycles with the Titanium Ranger riding in the Red Rescue Speeder  
This shot of Shockatron is when it goes back to Sentai footage.
Any time you see the Titanium Ranger, it's new footage but you should know that by now.
Once you see the Red Ranger fighting the Batlings by himself, it's back to Sentai footage.
Once it cuts to a shot of the Titanium Ranger fighting the Batlings, that's when the new footage starts back up again.
All footage of the 5 Rangers fighting Shockatron with their V-Lancers is new footage which includes the shots of him blowing up as well as the shots of his debris raining down.
In GoGoV, the Blue Ranger calls for the Rescuebird and fires the Unilaser all by himself. The Unilaser is what destroys Shockatron in GoGoV.
This shot is when it goes back to Sentai footage.
All Giant footage is Sentai footage.
All exterior shots of the planets in the solar system is Sentai footage.

NOTE: I can say for sure that most Skull Cavern interior shots in this episode are new footage however I can't be too sure of the first shot you see of Vypra and Loki in the Skull Cavern after we see an exterior shot of the planets in the solar system.

Sentai info comes from GoGoV Episode 14