Hello there,
Let me turn on my PA-80 and I will write everything step by step, here we go,

1.Turn on your PA-80 (8>)
2.we are in performance 1-1 now hit menu choose input/pad,
3.press page + once now we are at page 23,
4.now I am seeing assigned sounds to each pad,
5.I have changed pad 1. Crash 1 to pad 1. Crash 2,
6.now I have pressed write and click on STS 1 and press enter twice and I am back to page 23 now,
7.I have changed page 1.crash 2 (which we previously changed from crash 1) to 1.china now I have hit write again this time I am going to write on STS N. 2 hit enter twice, now I am pressing exit to return to main menu,
8.now when I press pad 1 in STS 1 I hear crash 2 and when I press STS 2 I hear china on pad 1 now I will save the performance and will turn off the keyboard.
9. now I have turned on my keyboard again and in STS 1 I hear crash 2 and when I press STS 2 I hear china on pad 1.
10. now I hope that you get the same results.
Kind Regards,