After the screen goes dark, it is still aparent that the display is
accurately
displaying the signal provided (e.g. you can see the ghost of the mouse
cursor moving around in response to mouse actions; you can double click on
icons and see those applications open, etc) -- but obviously the backlight
is no longer on (at all!)

There are two flourescent tubes in the display (?). Both are behaving
identically.

Each tube is excited from it's own inverter (i.e. the inverter board
appears
to have two identical circuits on it).

So, it seems logical to assume that the supply to the inverters is a
likely
suspect. Or, some control signal shared by both inverters (?).

As suspected, the problem was in the power supply (since it would
be highly improbable for *both* bulbs to fail in the same manner
*or* both inverters to fail, etc.). An electrolytic in the 12V supply
to the inverter was lossy and resulting in poor regulation of that
supply.

Didn't have a 470uF/25V/105C cap on hand but a 330/25/105 cap
proved my point -- I'll just have to remember to order some and
replace that (along with the few others onboard... a cheap prophylactic).

Thanks!


[email address is bogus]


Excellent job!

But this is unusual. Sounds like this LCD using low quality caps.
Most LCD panels tend to use good stuff due to space limitations.

If you don't have a cap for this value either voltage or uF, match
either and upsize the other values or both one level or more for
filter stuff.

Cheers, Wizard