SensingRebuild shelfUnplug and unscrew

Potentiometer

Also called pot, volume knob, throttle pot, trimmer.

A resistive divider with a knob. Volume pots, trim pots on boards, the trigger of a cordless tool, the stick of a gamepad. Gamepad sticks are often discarded because this part drifted. Test before you keep a stick.

If you are new to this category

A sensor reports a condition such as weight, light, temperature, or position. Many sensors do not switch fully on or off. A kitchen scale bar, for example, changes by thousandths of a volt. Keep the small board that read the sensor if you still have it.

Keep the connector. Write down the wire colors before you cut them. If you do not know which wire is which, the sensor is hard to reuse.

Four wires on a scale sensor

Red and black feed the sensor a steady few volts. Green and white are the tiny signal, measured between them, not from either one to ground. Pressing the bar changes that signal by millivolts. A normal meter on DC volts can show that it responds. Turning it into a number on a screen wants a small amplifier board, often an HX711.

Specification. The right-hand column is what is typical. The label on the part in your hand wins if they disagree.
What to look for	Usual figure
Audio taper	Marked A (log). Linear is B. A volume pot is a bad position sensor.
Values	1 k, 5 k, 10 k, 50 k, 100 k are common. The stamp reads like B10K.
Tool trigger	Often 2–5 k linear, plus a switch that closes at the start of the pull

Volts are electrical pressure, amps are how much current is flowing, and ohms are how hard the part resists that flow. A higher voltage than the part was built for is how salvage parts die on the bench. If a cell in the table says “read the stamp”, that stamp is the whole specification.

What people actually use it for

A panel control
A position signal if it is linear and still smooth

Leave this one when

The wiper crackles. Contact cleaner is a stay of execution, not a pardon, for a worn carbon track.

Buying a new one is the better idea when

A new pot of the right taper. Crackling in the audio path is not character.

How to tell if this one still works

Resistance end to end should match the stamp and stay still. Wiper to one end should move smoothly as you turn, with no jumps.

Tools you will want: Meter.

Where people actually find it

5 notes, most useful first. “Leave it” means the part is in that machine and you should not take it: it is dangerous, worn out, or only useful if you already know that exact repair.

Harvest at a glance
From	Call	How many	How often	Where it sits
Game controller	Worth it	2	usually	The sticks.
Clock radio or stereo	Worth it	2–4	usually	Volume, tone, balance.
Powered or Bluetooth speaker	Worth it	1	usually	Volume.
Cordless drill	Worth it	1	usually	The trigger.
E-scooter or hoverboard	Bonus	1	sometimes	Thumb throttle.

Worth pullingGame controller2 · usually
In this particular machine
Dual axis, often the failed part.
Where to look
The sticks.
How to get it out
Test for smooth resistance before you keep them.
The condition to expect
Drift is the common fault.
Worth pullingClock radio or stereo2–4 · usually
In this particular machine
Log taper on volume.
Where to look
Volume, tone, balance.
How to get it out
Scratchy is common.
The condition to expect
Clean is a maybe.
Worth pullingPowered or Bluetooth speaker1 · usually
In this particular machine
Log taper, often with a power switch.
Where to look
Volume.
How to get it out
Scratchy.
The condition to expect
Mixed.
Worth pullingCordless drill1 · usually
In this particular machine
Linear, plus a switch.
Where to look
The trigger.
How to get it out
Smoothness test.
The condition to expect
Wear is a common fault.
Bonus, if you are already in thereE-scooter or hoverboard1 · sometimes
In this particular machine
A hall throttle is more common than a pot. See hall sensors.
Where to look
Thumb throttle.
How to get it out
Keep it whole.
The condition to expect
Good.