I have a Satellite Pro where the display has gone very dim. I've read
where this can be the backlight, and I've read where this can be the
inverter. Are these totally separate parts (I've found pics and can't
tell if the backlight might be part of the inverter assembly) and is
there an easy way to figure out which it is?

Thanks,
Joe

Joe D wrote:
The backlight is a cold cathode fluorescent light and the inverter is a
high voltage supply board for the light. In the olden days, maybe two
or three years ago, the inverter was ("reportedly") the predominant
cause of screen dimming - it gets quite hot and heat is not good.
Currently, the light is ("reportedly") gaining on the inverter, but it
seems that lights usually fail to a black screen if posted reports are
accurate. So dimming is directionally the inverter, but lights can also
become dim and show color shifting. The inverter can fail outright and
leave the screen equally as black.

The inverter is the easiest part to replace, IMO. It is usually located
under the screen bezel between the hinges. You can feel the heat. Both
parts can be impossible to find for some laptops. The usual posted
advice is to leave the light to the professionals, FWIW. I have found
inverter boards on eBay - usually fairly well aged but working at least.
Lights are very hard to find. You might find complete working screens.
"Reputable supplier" is an oxymoron on eBay so if you can find an actual
OEM parts supplier I would recommend paying the price for both light and
inverter board.

Q

Thanks for the response. From the pictures I've seen, it looks like
the inverter is just a plug or two, whereas the backlight requires
soldering - is that right?

Also, if the inverter is what generates a lot of heat, does that mean I
can feel the back and if it's not warm, know that the inverter isn't
working? Or is it more likely to still get hot even when it's not
working correctly.

Thanks again,
Joe

Yes, they are totally separate, and there's no really easy way to figure
out which part is causing this symptom.


Joe D wrote:

Joe D wrote:
The inverter is simply two plug connections - one at each end. You can
feel the heat from the keyboard side, right in the middle of the bezel
between the hinges. From what I've seen, unless the inverter is
completely dead, you can feel the heat. OTOH, if the lamp is
inoperative, then the inverter has no output also. Like I said, it used
to be inverters that failed regularly. It is likely that this is still
the case, but you never know...

Q

Easy way to check backlight operation? Pull the screen and plug the
backlight into a known working laptop and inverter.. The CCFL's arent
propietary for the most part and if it does not fire up its the bulb..
We can replace the backlight if you need help (requires splitting the
screen asy apart) and the inverter is not hard to change if you'd
like to do this yourself.. (POWER UNPLUGGED AS WELL AS BATTERY
PULLED).. If you need help yell. Ken
www.ikenfixit.com

I would generally disagree with the assertion that you can feel the heat
from the inverter. This will depend on the inverter, of course, but his
experience isn't mine. The inverter is often to the side of the screen,
sometimes below it, sometimes in back of it. The actual TFT lamp (or
lamps -- some screens use two) may give off as much heat as the inverter.

Even if the lamp has failed, even if it's disconnected, the inverter may
still be operating, although it won't be generating much power.

Both the lamp and the inverter are normally "plug in", although when
replacing a lamp, the replacement lamp may or may not come with leads
and a connector already attached (if it doesn't, you may have to solder
the old leads to the new lamp).

The difficult part of replacing the lamp is that on some TFT panels,
lamp replacement is extremely difficult, even bordering on impossible
(on other panels, it's one or two screws and takes 20 seconds).

There is just so much model-to-model variability here that you really
just can't generalize about much of anything.


Quaoar wrote: