Test the keyboard key by key
Pick your keyboard’s size above the keys: 25, 32, 37, 49, 61, 76 or 88. The range line shows which notes it expects, for example notes 36 to 96 for a 61-key controller with no octave shift. If your keyboard’s octave buttons are pressed, notes arrive outside the drawing: press Fit to the keys I played after playing the lowest and highest key, or use the octave buttons here.
Then play every key twice, once as softly as you can and once hard. Each key turns green when it registers, and Dead keys counts down to zero. A key that stays grey, whatever you do, isn’t sending anything.
Hear what you play
Press Turn sound on to play the keyboard through the built-in synth: piano, electric piano, organ or a synth pad. It follows velocity, the sustain pedal (CC 64) and pitch bend (±2 semitones), so you can hear a key that plays too quietly, a pedal that doesn’t hold, or a wheel that doesn’t return. Sound starts off and only begins after you press the button, so the page never plays anything unexpected.
Velocity: the chart under the keys
The chart under the keyboard draws one bar per key, from the softest to the hardest note it has sent, with a tick at the last one. Most keys should look alike. A bar that stops well short of its neighbours marks a worn contact or sensor, and a key stuck near 127 usually has a dead first contact: velocity sensing keyboards time the gap between two contacts (three on many hammer actions), so losing one makes every press look instantly fast. The tester flags both kinds in orange.
Pedals, wheels and aftertouch
Press the sustain pedal and watch Sustain pedal switch between Up and Down. A continuous or half-damper pedal sends values in between, which the control list below the checks shows as coverage. Move the mod wheel and pitch bend to both ends. If your keyboard has aftertouch, press a held key harder: channel aftertouch shows one value for the whole keyboard, polyphonic aftertouch names the key.