On Mon, 11 Feb 2008 06:44:09 -0800 (PST), sck0006
wrote:

We have a TDS 220, S/N B070664, with a very dim backlight. It seems
stable, just very dim. The inverter measures 201VAC w/ the backlight
connected, 205V without. Is it safe to assume the tube is bad?
Tektronix charges $73.00 for the part now, as they no longer sell only
the tube (P/N 119-5585-00), it apparently now comes with the whole
plastic assembly (P/N 199-4991-11). Is there anywhere to still buy
just the tube? It lists the Mfr p/n for the tube as LM0F2964, MFG is
LF2569 (Sharp Corporation). Thanks for all help,

Just speculating, but it may be that the assembly is an overall
upgraded backlight. The TDS220 I have at home still works beautifully
but one at (a prior) lab that I used was quite dim from the start.

--
Rich Webb Norfolk, VA