B
bill
Guest
I have a client who has a Toshiba 1805-S274 laptop, about two years
old. The LCD back light starting giving her problems, so she brought
it to me for repair. Upon initial examination it appeared the cover
switch was causing the problem, as I could get the back light to come
back on if I tweaked it a bit. My plan was the "cheap" fix, to just
disable the switch since my client does not need the close cover
function.
Unfortunately it turned out the problem is not in the switch. What I
discovered is that if I set the laptop's LCD brightness level to it's
highest level, the back light would not work, or it would not work
reliably. If I knocked it down a notch (i.e. from Super to Bright) it
would work 90% of the time, but not always.
I've come to the conclusion the problem is likely the florescent
tube(s) or the inverter. I don't know how many florescent tubes there
are in this panel, but I assume there are more than one. When the
back light goes it the whole panel goes dark, not just a section (I
can still see the image on the LCD, very faintly, so I know the LCD is
still working fine). Therefore I'm going to try replacing the
inverter first, which also happens to cost a LOT less than the
florescent tube(s).
By the way, I have check the connections for loose or broken cables
and they are in good shape. The laptop operates flawlessly otherwise.
Any comments as to my diagnosis? (Yes, I know I can stick a voltmeter
on the output of the inverter but I didn't want to bust open the LCD
case just yet -- the client won't let me keep it in the shop for more
than a couple of hours at a time!). The cost of the inverter is
around $80, much more reasonable than a complete LCD replacement,
which is what Toshiba would do if we sent it in for out of warranty
repairs.
-Bill
old. The LCD back light starting giving her problems, so she brought
it to me for repair. Upon initial examination it appeared the cover
switch was causing the problem, as I could get the back light to come
back on if I tweaked it a bit. My plan was the "cheap" fix, to just
disable the switch since my client does not need the close cover
function.
Unfortunately it turned out the problem is not in the switch. What I
discovered is that if I set the laptop's LCD brightness level to it's
highest level, the back light would not work, or it would not work
reliably. If I knocked it down a notch (i.e. from Super to Bright) it
would work 90% of the time, but not always.
I've come to the conclusion the problem is likely the florescent
tube(s) or the inverter. I don't know how many florescent tubes there
are in this panel, but I assume there are more than one. When the
back light goes it the whole panel goes dark, not just a section (I
can still see the image on the LCD, very faintly, so I know the LCD is
still working fine). Therefore I'm going to try replacing the
inverter first, which also happens to cost a LOT less than the
florescent tube(s).
By the way, I have check the connections for loose or broken cables
and they are in good shape. The laptop operates flawlessly otherwise.
Any comments as to my diagnosis? (Yes, I know I can stick a voltmeter
on the output of the inverter but I didn't want to bust open the LCD
case just yet -- the client won't let me keep it in the shop for more
than a couple of hours at a time!). The cost of the inverter is
around $80, much more reasonable than a complete LCD replacement,
which is what Toshiba would do if we sent it in for out of warranty
repairs.
-Bill