~misfit~ wrote:
Has anyone done this? My beloved Dell 2007FP (20" 4:3 UXGA [1600x1200] IPS)
monitor is getting dim. I've been having to use it on full brightness for a
while now and even then it's not bright and takes a while to reach full
brightness, maybe 15 seconds.

I'm not rich but could swing a few hundred for a new monitor if I absolutely
had to. However I've been spoiled with this monitor and nothing that I can
afford even comes close to being as good. I've got a multimeter, soldering
iron and more than half a brain and would much prefer to keep this montior
out of a landfill.

I've seen a few kits for sale to do the job (this is a cheap one
http://www.aliexpress.com/item/15-23...252220243.html )
but would feel better knowing that someone else here had successfully done
this mod. Also I'm concerned that, as IPS monitors don't transmit as much
light as TN monitors I might need a brighter than usual backlight.

Thoughts?

I'd stick with replacing with "like" technology.

And that's assuming there is actually an inverter or CCFL problem,
and not a problem with the PWM control signal or the power supply.

Odds are, it is an inverter/CCFL problem, with inverters being the
highest probability of failure.

The panel uses multiple CCFL tubes and multiple
inverters. A big panel might use four inverters and
sixteen tubes for example. Now, consider the failure
possibilities. If one CCFL tube turns brown before
the others, you'd notice a non-uniform display. Or,
if one inverter failed, a quadrant of the screen
would go dim. Given such a situation, is the
entire panel going dim ? Would all the inverters
"go on vacation" at the same time ? Unlikely.

Common points of failure, would be the PWM signal
(pulse width modulation, 200Hz, high for 66 cycles,
low for 134 cycles would be 33% intensity setting).
Or, perhaps the 12V power source feeding the inverters
is out of spec. If that was the case, maybe other
circuitry would suffer as well. There have been
monitors with poorly design supplies, power supplies
with leaking electrolytic capacitors. It would be
a shame to waste $100 on LED kits, only to find
the problem was a bad power supply.

I heartily recommend repairing things, where you
can "bound" the repair cost, and see ways of
preventing the repair bill from shooting too high.
Obviously, it's a personal judgment call, as to
how far to push this. If the monitor cost $1000,
I might consider making two repair attempts (CCFL
first, LEDs later if the CCFL didn't work out
for some reason). If the monitor cost $300, I'd
probably just bin it.

Those LED kits don't seem to have a diffuser in
evidence. How will the "ripple" in light intensity
from all those point sources be handled ? Will
the panel look like a "cheese grater" when displaying
an all-white background ?

The very last thing you want, is a repair job
where you're "reminded" every time you look
at the monitor, that you've fouled things up :-)
I know that feeling (the less than perfect repair).

Paul