Error Starting PL! (Korg PA800)

[Korgloveforever]

Hi all.

Please help if you know how to solve this!
I tried to load a new patch on my pa800 and it froze half way. So I had to power off and turn it on again. When I did that the operating system would freeze and wouldn’t load. So I tried to install a new OS by pressing intro 1 key while turning on the keyboard but that failed to work. So I started reading about this in different forums when I came accross a post suggesting formatting Nand. So I did that and I received a message saying "zero bad sectors".
After that I tried to hold Intro 1 while turning on to install a new OS but I keep getting an error saying “Error Starting PL!
I even tried 5 different usb drives, including and old 1 Gb one but no luck.
I am stuck here and I can’t get my keyboard working.

Please help if you know how to solve this problem.
Thank you in advance.