Korg Forums

[snappygraham]

The sustain pedal has stopped working or works intermittently. In addition the sustain effect comes on randomly in mid tune with no foot on the pedal. Have tried pressing down pedal with no effect.

This feels like an electrical fault rather than a settings issue. Is it repairable by me as a novice? The piano has been left out in its soft case in the car for a couple of nights: maybe temperatures might effect contacts. However it has been inside for 5 days now with no return to normal? Any thoughts?

[voip]

What happens if the sustain pedal is disconnected?

.

[snappygraham]

Whether the plug is in the damper socket or not makes no difference.

[voip]

At least that rules out the pedal.

If you have access to a DC voltmeter, connect a jack to jack mono cable to the Damper port and measure the voltage between tip and sleeve. It should be 3.3V, or thereabouts. Ensure the plug contacts are clean for these measurements. When the sustain effect comes on randomly, check again to see what the voltage is. If the voltage is less or varies, it suggests a possible loose internal connection, or current leakage somewhere in the Damper pedal circuitry.

.

[snappygraham]

What I've now realised is that if I put the plug in firmly, the sustain pedal works so as you say there must be dirt or a loose connection in there. Is it straightforward to inspect the socket?

[voip]

One possible remedy is a good clean, using some contact cleaner spray like Servisol Super 10, or there's a similar Deoxit product. Apply some to a jack plug, insert into the socket a few times then withdraw, wipe the plug with tissue, note the amount of gunk, and repeat, until the tissue comes clean. A quick blast of canned "air" inside the jack socket might also dislodge something, if the contact cleaner trick doesn't work. It goes without saying that the plugs need to be kept clean, too. If one jack socket is showing such signs, it's worth doing the same to all the other sockets.

I had audio issues with a Kronos a while back. The remedy was as described above.

If the problem persists, then it is possible that the solder joints between the socket and circuit board may have come adrift, especially if the cable has been pulled sideways by accident.

.

[snappygraham]

Ok thanks. Have ordered a can and will try it out.