Does anyone know if there is an internal switch on the dgx500 to allow for both the internal speakers to work as well as the output to a pa? This board has only one output...combination phones/output? Appreciate anyone who can help.

Although I can't help you with your problem maybe you could try asking it on the General Arranger Keyboard Forum here on the BBS. Maybe George Kaye ( who is a dealer of Yamaha keyboards ) will be able to advise you.