Yamaha DGX-640 Owner's Manual - Page 109

Troubleshooting Appendix For the Instrument Problem When the instrument is turned on or off, a popping sound is temporarily produced. When using a mobile phone, noise is produced. There is no sound even when the keyboard is played or when a song or style is being played back. Playing keys in the right hand area of the keyboard does not produce any sound. The style or song does not play back when the [START/STOP] button is pressed. The style does not sound properly. No rhythm accompaniment plays when the [START/ STOP] button is pressed after selecting style number 136 or a style between 148-165 (Pianist). Not all of the voices seem to sound, or the sound seems to be cut off. The footswitch (for sustain) seems to produce the opposite effect. For example, pressing the footswitch cuts off the sound and releasing it sustains the sounds. The sound of the voice changes from note to note. There are Japanese characters in the display messages. The appropriate display does not appear when the [SONG], [EASY SONG ARRANGER], [STYLE], or [VOICE] button is pressed. The wrong notes sound when the keyboard is played. The ACMP indicator does not appear when the [ACMP ON/OFF] button is pressed. The "OverCurrent" message is shown in the upper area of the MAIN display and the USB device does not respond. Possible Cause and Solution This is normal and indicates that the instrument is receiving electrical power. Using a mobile phone in close proximity to the instrument may produce interference. To prevent this, turn off the mobile phone or use it further away from the instrument. Check that nothing is connected to the PHONES/OUTPUT jack on the rear panel. When a set of headphones is plugged into this jack, no sound is output. Check the Local Control on/off. (See page 98.) Is the FILE CONTROL display showing? The instrument's keyboard, etc., will not produce any sound while the FILE CONTROL display is showing. Press the [EXIT] button to return to the MAIN display. When using the Dictionary function (page 82), the keys in the right hand area are used only for entering the chord root and type. Is External Clock set to ON? Make sure External Clock is set to OFF; refer to "External Clock" on page 98. Make sure that the Style Volume (page 79) is set to an appropriate level. Is the split point set at an appropriate key for the chords you are playing? Set the split point at an appropriate key (page 80). Is the "ACMP" indicator showing in the display? If it is not showing press the [ACMP ON/OFF] button so that it does show. This is not a malfunction. Style number 136 and style numbers 148-165 (Pianist) have no rhythm parts, so no rhythm will play. The other parts will begin playing when you play a chord in the accompaniment range of the keyboard if style playback is turned on. The instrument is polyphonic up to a maximum of 64 notes. If the Dual voice or Split voice is being used and a style or song is playing back at the same time, some notes/sounds may be omitted (or "stolen") from the accompaniment or song. The polarity of the footswitch is reversed. Make sure that the footswitch plug is properly connected to the SUSTAIN jack before turning on the power. This is normal. The AWM tone generation method uses multiple recordings (samples) of an instrument across the range of the keyboard; thus, the actual sound of the voice may be slightly different from note to note. Make sure the Language setting in the FUNCTION display is set to English. (See page 71) Is another display showing? Try pressing the [EXIT] button to return to the MAIN display, and then pressing one of the mentioned buttons. Perhaps the performance assistant technology is turned on. Press the [P.A.T. ON/OFF] button to turn it off. Always press the [STYLE] button first when you are going to use any style-related function. Communication with the USB device has been shut down because of the overcurrent to the USB device. Disconnect the device from the USB TO DEVICE terminal, then turn on the power of the instrument. Appendix Owner's Manual 109