Back up any files you want saved.
Download these two files from
www.korgpa.com :
http://www.korgpa.com/pa_root/software/ ... format.zip
http://www.korgpa.com/pa_root/software/ ... s_v201.zip
On your computer extract these two files and copy them to the root folder of a USB stick :
Pa800_reset.pkg
Pa800_os_res_v201.pkg
Power off your Pa800, insert the usb stick, power on while holding down the INTRO1 key, select the file Pa800_reset.pkg.
Then power off again, power on and select the file Pa800_os_res_v201.pkg, when it finishes power of an on again.
Now your Pa800 will be fully working and reset to factory defaults for everything.
Regards,
Rob
I took my Korg Pa800 into the shop in Sacramento for warranty work on the power amplifier. After 3 months of wrong parts, back-ordered parts, etc. Korg refused to replace it and made me wait. I just got it back. Now I am unable to disconnect the speakers. I went to: Global/Audio Set Up/MET/MP3 Speakers/ and unchecked the "Speakers On/Off" box. I then re-installed the factory format, OS and REV files which are fresh off of the Korgpa.com website. No help. Any suggestions??? 
