Exploding tricorder

[Henoch]

So what you have left for an explanation are components under the right conditions that can be overloaded and explode, like those present in a phaser or engine or even a TOS circuit (not circuit board), and energies that can build up such an overload to cause an explosion... both would be consistent with what has been shown in TOS

It's all about the technical basis behind every important piece of equipment, the transtator. From Piece of the Action:

SPOCK: Captain. If the Iotians, who are very bright and imitative people, should take that communicator apart
KIRK: They will, they will. And they'll find out how the transtator works.
SPOCK: The transtator is the basis for every important piece of equipment that we have.

I assume it's the transtator circuitry (which by chance look a lot like transistors ) that may involve extreme high power (and is potentially explosive). YMMV

Also, another "overload" could be in The Alternative Factor when Lazarus fiddled with the high voltage panel to cause the Dilithium Crystal Energizer Station to explode:
https://tos.trekcore.com/gallery/al...ernative-factor/alternative-factor-br-425.jpg
https://tos.trekcore.com/gallery/al...ernative-factor/alternative-factor-br-440.jpg