[TenTec] delta II backlight - what is it called?

[Stuart Rohre]

John,
I think it is called electroluminescent strip.  You might also check for 
a bad electrolytic by pass cap on the display board power bus.  That 
could be causing noise on the DC and upsetting the proper operation of 
the display
Bridge a new cap across the old with proper polarity, and check the 
waveform and the voltage for being right on with no noise before you 
remove that expensive (time intensive) driver chip.

GL and 73,
Stuart Rohre
K5KVH