If your keyboard sustains all the time when your foot is off the pedal, and then stops sustaining when you press it, you have the classic “reversed sustain” problem. The good news is that it’s almost always a setup/polarity mismatch and not a hardware failure.
On many Yamaha instruments the pedal’s polarity (open/closed) is detected at power‑on, so a single startup sequence can flip the behavior by accident.
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What can you try first?
Restarting the keyboard
Sometimes, the issue is that the pedal came briefly disconnected, or was plugged in while the keyboard was on. If this is the case, you can follow the below routine:
- Turn the instrument off.
- Plug the sustain pedal into the dedicated SUSTAIN jack if one exists, or into the PEDAL jack if it doesn’t.
- Power the keyboard on, and do not press the pedal while it’s powering up!
If the behavior persists, there are two possibilities. First, you might have a damaged pedal—an intermittent pedal cord can cause strange symptoms. Second, you might have the wrong pedal! There are two kinds of pedals, described below.
Checking for a pedal polarity switch
Many aftermarket pedals on Amazon have a switch on the bottom that allows you to change the polarity. The switch will typically have two positions, and these will be marked NC (normally closed) and NO (normally open), or will have a picture of a single line and a broken line. Try reversing the position of this switch.
So why does this happen?
Polarity mismatch (NC vs. NO)
Yamaha and Roland keyboards are designed to use a normally closed (NC) switch for on/off sustain pedals. Conversely, Korg and Casio typically use normally open (NO) sustain pedals. Using the wrong pedal—or starting up while the pedal is held—can invert the logic.
Powered‑on while the pedal is depressed
Some keyboards will cleverly try to “learn” the pedal state at startup. If your foot is on the pedal during power‑on, sustain behavior can be reversed until the next correct startup. If this happens to you, just turn the keyboard off and back on again.
Using an expression pedal in place of a sustain
An expression/volume pedal (continuous variable controller) plugged into a sustain jack won’t behave like a simple on/off damper switch and may work in reverse, or not at all.
Which pedals should I purchase?
M-Audio SP-2 Universal Sustain Pedal
This pedal is an excellent all-around choice, and can be easily switched between NC and NO. It will work for Yamaha, Roland, Casio, Korg, and other keyboards, and I recommend it to customers regularly. The build quality is also very good, far exceeding that of inexpensive or generic pedals. Pedals do, after all, live a rather challenging life: They’re literally getting stepped on! The M-Audio SP-2 is available on Amazon.
Yamaha FC5 (Compact Sustain Footswitch)
The FC5 is Yamaha’s rugged, compact switch pedal used for sustain (damper) or other on/off functions. Because it’s designed by Yamaha, it has NC polarity. This is the right choice when you want a simple sustain pedal and don’t need half‑pedaling. It’s inexpensive and durable. The Yamaha FC5 is available on Amazon.
Yamaha FC7 (Expression/Volume Pedal)
The FC7 is a continuous expression pedal (variable resistor) for volume, expression, or other assignable parameters. It features an adjustable pedal angle and a “fortissimo” spring‑return range for dynamic accents. It connects to a keyboard’s FOOT CONTROLLER / expression jack—not the SUSTAIN jack. The Yamaha FC7 is available on Amazon.
