Invertor or Screen

[Glenn Clark]

Hi All

What's the best way to tell if the invertor is faulty or the lcd screen. I
have a Dell laptop and have no display and need to order replacement parts

Many thanks

Glenn

 

[Dani]

Unless the screen is actually damaged, it's not bad! Try the unit in a
dark room, to see if the
screen comes on momentarily! If it does, it could be a bad lamp, a
couple of lamps, or the ballast, or even the SMPS (switch mode power
supply)! You can't safely measure the power from the ballast to the
lamps! You MAY see swollen capacitors in the SMPS. Without spare parts
to try, it's hard to tell exactly which part is bad! Hope this helps,
Dani.

 

[Neilish]

Unless the screen is actually damaged, it's not bad! Try the unit in a
dark room, to see if the
screen comes on momentarily! If it does, it could be a bad lamp, a
couple of lamps, or the ballast, or even the SMPS (switch mode power
supply)! You can't safely measure the power from the ballast to the
lamps! You MAY see swollen capacitors in the SMPS. Without spare parts
to try, it's hard to tell exactly which part is bad! Hope this helps,
Dani.

I havent actually tried this but read it somewhere (possibly the FAQ) that
if it was the backlight that was bad you could shine a bright light at the
screen and see a picture (assuming it was powered up and connected to an
input of some kind) this obviously rules out the lcd but you still have to
find out if its a bad inverter or bad ccfl

cheers
neil

 

[James Sweet]

I havent actually tried this but read it somewhere (possibly the FAQ) that
if it was the backlight that was bad you could shine a bright light at the
screen and see a picture (assuming it was powered up and connected to an
input of some kind) this obviously rules out the lcd but you still have to
find out if its a bad inverter or bad ccfl

It works, but you need a really bright light, sunlight works well.

 

[jonpi]

the one and only test is to put a known good test bulb on it...anything
from a scanner or other lcd ... be sure to note insulation where you
make the connection since 1kv will arc if not good...and then oh oh

i am asking now...anyone...do the bulbs have polarity...i did just look
at the electrodes from a dead one (crunched off the glass) and they were
different...one was hollow ... the other looked solid and noticabely
burned at the tip ... one of the several bulbs I have seen had a
marking on one end ..C1 or it might have been C2

 

[JANA]

If the screen has lamps that can be changed, it is best to change both the
lamps and inverter at the same time. After a number of years of use, the
inverter can also fail.

--

JANA
_____


Hi All

What's the best way to tell if the invertor is faulty or the lcd screen. I
have a Dell laptop and have no display and need to order replacement parts

Many thanks

Glenn