Five minutes is genuinely enough if you go in a fixed order, and doing it in front of the seller is the right call. Bring a USB cable that you know carries data, because a charge-only cable will waste your visit.
The order matters, because it puts the expensive faults first.
Start with the sticks at rest. Put the controller on a flat surface, hands off, and read the resting values. Under 0.03 is healthy, 0.03 to 0.10 is used but serviceable and worth a lower price, above 0.10 means it needs a module and you should either walk away or pay accordingly. This is the single most important reading because it is the most common fault and the most expensive to ignore.
Then the mid-travel noise: hold each stick at half deflection for ten seconds. A tight band means the track is in good condition, a visibly jumpy value means wear is well advanced even if the resting figure looks acceptable. This is the check that catches a controller about to fail, and almost no buyer does it.
Then the fast stuff. Every face button, both bumpers, all four D-pad directions, both stick clicks and the Start, Select and Options buttons, pressed firmly once each and then lightly once each. Light presses catch worn membranes that firm presses hide. Both triggers from rest to fully pulled, checking a clean 0.00 at rest and a smooth climb to 1.00. Then both rumble motors.
What makes me walk away: resting value above 0.10, any input that does not register on a light press, a trigger that does not reach 1.00 or does not rest at 0.00, a silent rumble motor, or a charging port that only works at an angle. What is negotiable: a worn-looking shell, mushy buttons that still register, and a tired battery, all of which are cheap to fix and reasonable grounds for a lower price.
