[Scott20]

Hello,
Well I'm currently having an issue with my laptop most likely to do with the backlight. What has happened is I was visiting my father and he decided to borrow my charger for his toshiba laptop. Well is charged sure enough but when I came back to find he had used it the charger wasn't in the best of conditions. Anyway I had to continue using it until a replacement would arrive, meanwhile the USB ports would have a light flow of electricity running through them (lovely and safe eh?)
Anyway now to the screen issue. I turned my laptop on the other day to find that the backlights came on for around 4 seconds then shut off. I let windows load and after playing around with switching the screen on and off (by changing the video card output between an external monitor and the laptop screen) I managed to get the backlights to stay on. Though there was now a slight buzzing noise that got louder the more the brightness was turned down. Also there is a slight flicker in the screen that lessens the more the brightness is turned down.Now most times I turn the screen on the backlight doesn't work unless I flick the screen on and off a few times. Today however it simply refused to turn on at all. I mean I can flick through and make the backlights turn on for a few seconds but they are at full brightness and then simply turn themselves back off again.
So what I really need to know is what the problem most likely is. Is it the backlights or is it something else? Thanks in advance for your time and effort.

 

[TriggerFinger]

hi,

it could be the inverter or the backlight. if you hear a buzzing sound when the backlight is ON, then it could be the inverter.

 

[Scott20]

Actually yes there is a buzzing noise. Since I wrote the post the backlight refuses to turn on now at all. But anyway, there was a loud buzzing noise. So now that I have a good idea of the problem I will look around for an inverter. If anyone has any knowledge of them I would appreciate some info. I have repaired many desktops in my time (worked as a repair tech when I was staying in the USA for a few years) but this will be my first time working on a laptop.

 

[TriggerFinger]

do you still hear the buzzing sound? does it come from the LCD / the top lid? i ask because you could be hearing the fan.

 

[Scott20]

Ah that made me laugh a bit to read that, thanks for the concern but it is coming from the LCD (well just at the very base of it) It's not the type of buzzing noise a fan ever makes it's more high pitched, not really sure how to explain it. Also the sound is never made when the backlights are off. I had my suspicions it was the inverter before I posted on here I just needed a second opinion. If at all possible I could do with some more info on inverters from anyone who has replaced one before. Thanks again for anyone who can give some info of this.

 

[TriggerFinger]

it's better to be sure. :grin:

an inverter looks like this .

easy to replace. best if you have a service manual to guide you in the removal and replacement procedure.

 

[Scott20]

I was just looking for a service manual earlier. Thanks for the pic though that will help a lot. Heh can't wait until I can see my screen again! Is annoying having a desk lamp aimed at the screen =p

 

[TriggerFinger]

good luck then. let's hope your backlight is still good as this one is a pain to replace, well at least for me.

 

[petercc]

Hi All,
I'm new to this forum and looking for some advice please?
I was trying to fix my friends Laptop which is a Toshiba Euiium P200 139. The original problem was a pink/red tint on the screen, as soon as i took it away it, the back light wouldn't come on all but you can see the LCD is fine if you look really closely. So i thought it was probably the invertor or the backlight itself. I've replaced the invertor but it had no affect and i've replaced the CCFL twice and that's had no impact either so i replaced the entire screen and still no joy. Can anyone please suggest what else teh problem could be. I'm doing it as a favour but it's really starting to cost me!
Thanks,
Peter.

Oh and when you attach an external monitor via the VGA the external monitor works fine!
Thanks.