HP-15C LE bricked?

[Hans Brueggemann]

thanks for the hints, gentlemen.
problem solved, probably just by chance: didn't try batteries, but on a hunch, i lowered the supply voltage to the calculator down to 3.0V (previously 3.3V) and tried the entire flash process again. lo and behold, WP34sFlash.exe did its job, and the calculator is functioning normally.
btw, i was using a JLINK ultra+ in VCOM mode (yeah, i'm a tool snob).

edit: find attached the STL file for a CR2032 dummy. couldn't post it as *.STL, so i added a ".txt" to the name. covered top and rim with self-adhesive copper foil and soldered two wires to it to make a q&d battery adapter for testing.