Toshiba P855-S5200 dim display

[bufferjg]

I am trying to repair a laptop that has an issue with a dim screen. I can see the video card is sending the signal to the screen but the it is extremely dim both inside and outside of windows. I have replaced the screen and issue persists on new display. It is a led backlight lcd screen so there is no power invertor. Anybody have any idea what else it could be?

 

[gashonie]

You try FN key + brightness key and Power Options

 

[bufferjg]

You try FN key + brightness key and Power Options

Yes I did. External display also works fine as well. Gonna try replacing LCD cable but I doubt it is that.

 

[gashonie]

I think it is. Connection with motherboard if you have good picture on External, and you all ready replace screen.

 

[bufferjg]

I think it is. Connection with motherboard if you have good picture on External, and you all ready replace screen.

I will update thread of it solves issue. Ever heard of a fuse being blown on board that would cause the board not to send power to led backlight?

 

[jarotech]

Hi, yes you have a fuse F3 (3A-32V) on the motherboard.

 

[Tradesman1]

If not fuse, the cable would be the next - check first and ensure it has a good connection

 

[bufferjg]

New cable did not fix the issue. Anybody have any other suggestions?

 

[jarotech]

I gave you the answer, it's not the screen or the cable, the problem is the fuse F3. So what is you want more?

 

[bufferjg]

I gave you the answer, it's not the screen or the cable, the problem is the fuse F3. So what is you want more?

I am unable to locate the fuse. I assume it's under the LCD connector, but none labeled f3. Trying to locate schematics for this particular board.

 

[jarotech]

You have F3 for the fuse and L2 for an inductor around the screen connector, if I have the right schematics.