VFD rejuvenation USB 5V CD7220

[hakonon]

Salvaged this old POS display with a dim vacuum fluorescent display in it. This is USB 5V version, fully DC.
Been reading about these VFD rejuvenations possibilities.
I tried supplying around 11,5v DC from some old computer PSU do the outermost pins some seconds a few times.
Only a couple of the segment display areas from top left lit up, no general improvement in brightness.
I was under impression those filament lines/grids should start glowing instead.
Should I try more voltage to those same pins? I have no clue really.

This USB version is really easy to program with python.
I was thinking some chatgpt api app for fun, or maybe a guitar tuner or smth.