On the Subject of Yellow Arrows

Points!

On the module are 4 directional buttons, and a display screen in the middle.

If the buttons are not Yellow, you're looking at a different module.

On the display is a random English letter. That is your Starting Row. Then, take the last digit of the Serial Number plus one, and move down that many rows. Perform that instruction, and move down again by the same number (If Z is reached but you still have more down moves, loop back to A and continue). Keep doing that, and the module will be disarmed after 5 consecutive correct presses.

Pressing an incorrect button will register a Strike, and the module will reset itself with a new Starting Row, and you must start over.

Letter Press../If../Otherwise..
A Up/The Up button is present/Eat a Screwdriver
B Down/Previous input is Left/Right
C Left/The Serial Number ends with a 3/Up
D Up/This is the Starting Row/Down
E Right/Lit SIG present/Left
F Down/No (PS/2) port present on the bomb/Any
G Up/Down hasn't been pressed yet/Down
H Any/Serial Port present/Right
I Down/No Needy present/Any
J Left/Previous input was Down/Up
K Down/9 is an odd number/Go back to kindergarten
L Up/No batteries on bomb/Down
M Right/Number of battery holders is less than 3/Left
N Any/This is the Starting Row/Right
O Left/The Serial Number contains the letter O/Down
Letter Press../If../Otherwise..
P Down/Serial Number has 4 letters/Up
Q Down/Previous input was Right/Left
R Up/Unlit CLR present/Down
S Left/You're not on the 42nd of June/Quit Game
T Left/Number of batteries is even/Down
U Any/No modules on bomb starts with a Y/Any
V Up/Previous input was Up/Down
W Right/No port plates present/Any
X Up/This is the Starting Row/Left
Y Any/Up hasn't been pressed yet/Up
Z Right/Right is Right OR is on the Right/Right