Solution

To see how the 25 feeder answers can be grouped into 5 groups of 5 answers, one for each meta puzzle, refer to the solution page for “Base of Operations”.

As hinted by the title of this puzzle, the feeder answers required here are the names of modules that have a button labeled “CHECK”.

The symbols have five traits. Which symbols have which traits gives rise to Morse code:

Trait	Which symbols have it (# = yes, . = no)	Letter
Blue background	. . . # . # . # . . . .	S
Square frame	. . # # # . # . # . . .	D
Star shape	. # # # . # . # # # . .	K
Thick border	# # # . # # # . # # # .	O
Filled shape	. . . # # # . # . . . .	N

Each of these letters can be used to extend one of the three-letter answers to the provided clues into a four-letter word that is associated with one of the modules:

Clue	Answer	+	Word	Feeder answer
Math symbol for approaching a value	LIM	S	SLIM	CONNECTION CHECK
Vehicle indicator?	CAR	D	CARD	POKER
Pasture	LEA	K	LEAK	PLUMBING
____ Pinafore	HMS	O	OHMS	RESISTORS
First fruit-eating criminal?	EVE	N	EVEN	CRACKBOX

In the bottom part, each symbol has only one of the traits. Now that we can associate these traits with feeder answers, we can use the numbers to index into the appropriate feeder answer to obtain the solution.

BUTTON MASHER