Anyone have any experience with an Epson Stylus 500 that won't obey
any of the self test, clean commands etc that use its buttons, and
shows offline all the time in the status window? Also shows ink out
after changing ink cartridges.

Mike
I bought one for my daughter for college and she had the same problems.  I
read the manual and both are covered in the manual.  I must say you have to
do exactly as it says, one false move and I had to start over again.
Ron