Laptop Screen Problem

DatabaseError

My sis had a Toshiba laptop. Brought it round an hour or so ago with what first looked to be a duff backlight, but probably something a bit different.
I know some of you guys repair lappies, so, rather than jumping in with both feet I thought I'd better ask.

Symptoms

Power on the laptop, screen illuminates, "Toshiba" logo appears, screen darkens.
Once the machine has finished booting screen image is apparent, but very, very feint. Apparently shining a light onto it illuminates the text and graphics.
Almost closing the lid re-illuminates the screen briefly.

So..Ribbon cable, backlight or other?
Simple fix?
Lappy is a toshiba satellite U400-18S

Thanks

fwor

First thing I'd try is to rule out an obscure graphics software/driver problem by booting it from a non-Windows (assuming it's running a version of Win now) LiveCD. If you still see the same problem, it's 99.9% certainly hardware.

scottishblondie

If it is hardware, then it's most likely a broken cable if the backlight is flashing on at certain times. Although it could also be the inverter or the backlight itself. Does it come on at all if you move the screen around? (other than just when you open the lid)

GunJack

think fwor's on the right lines, try a live cd first just in case, but it deffo sounds like an intermittent cable, probably power supply to inverter board

Hammyman

DatabaseError wrote: »

My sis had a Toshiba laptop. Brought it round an hour or so ago with what first looked to be a duff backlight, but probably something a bit different.
I know some of you guys repair lappies, so, rather than jumping in with both feet I thought I'd better ask.

Symptoms

Power on the laptop, screen illuminates, "Toshiba" logo appears, screen darkens.
Once the machine has finished booting screen image is apparent, but very, very feint. Apparently shining a light onto it illuminates the text and graphics.
Almost closing the lid re-illuminates the screen briefly.

So..Ribbon cable, backlight or other?
Simple fix?
Lappy is a toshiba satellite U400-18S

Thanks

Possibly the cable (not the ribbon cablembut the one with the white and pink wires) but my guess is the inverter which is a small long rectangular circuit board that is attached to the bottom of the screen and powers the backlight. It can be swapped out seperately. Backlights rarely fail, its usually the inverter.

DatabaseError

Hammyman wrote: »

Possibly the cable (not the ribbon cablembut the one with the white and pink wires) but my guess is the inverter which is a small long rectangular circuit board that is attached to the bottom of the screen and powers the backlight. It can be swapped out seperately. Backlights rarely fail, its usually the inverter.

cheers for that - simple fix? inexpensive?

not seen sis since she brought it around (and took it back with her) but i think she won't have killed it yet)

So..ebay they're around £10, I guess i just need to find out which one is used in her lappy..and how to fit it.

Mondez

Its a fairly simply fix in theory, the inverter board is normally just below the screen under the plastic, take the old one out and put the new one in. The tricky part is taking it apart enough to fit it without breaking the plastic catches that hold the plastic coverings around the screen together. There are also some screws under the rubber feet normally around the screen.