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laptop backlight question? Answered

Long story short.  Room mate got bleach on his Toshiba laptop.  It spilled into the port of the usb area, hdmi, network cable side and he said it instantly cut off. He tried turning it on and the power light would just flick off. (he also borrowed my movie that i rented from the library)
 After drying it all day we took it apart and noticed the bleach had corroded the usb port. I remembered in my college days that shorting a usb port will cause power supply to cut off. So i said lets get some CRC QD cleaner and just clean the corrosion and it should work.
I couldn't get any electric cleaner but the people who work across the street had some non chlorinated break cleaner.  We used that to clean as much of the corrosion as possible off the usb and noticed some on two of the chips on the motherboard had corrosion.  Spent about 20 min cleaning each pin on the chips to separate them and tried powering it again. 
(at this point the laptop is mostly apart and just got bare essentials put together).  It worked, fans started spinning and screen flashed its toshiba windows didnt shutdown logo.
I begin to assemble it as much as possible without putting any screws in. I got the keyboard in and every electrical component.  i mashed the power button and the backlight on the screen wont come on.  I can see the text on the screen change but no light.
Take the keyboard out and it works normally. 

Can someone help me, or got any pointers?  I'm away from home so I dont have access to fancy equipment like tooth brushes or contact cleaner.



Best Answer 4 years ago

I would have used water to clean bleach up since its water based. But it sounds like you got it mostly cleaned.

I had a very similar problem and found that a little wire had gotten into a place between where the plastic faces meat up. When it was pressed together by putting the screws in the wire got shorted out. Look very carefully for something being out of place like that. Second, are your screws of different length? If you are putting a long screw in a place that was made for a short one it could be going through and touching another component. Screws in general are the ground for the platform so any live power that they come into contact with will dead short. If you are dead shorting the power to the back light then it will not come on.

i tested everything before i screwed anything down thats when i discovered the back light not coming on with the keyboard ribbon cable is inserted. I will check to see if i am pinching any wires.

will water remove corrosion? the bleach caused the corrosion almost instantly (within 3 hrs)

Bleach is water base and it won't get cleaned off with a solvent. That is why I would use water, it still might be there if you didn't and yes it does corrode pretty fast. Think of soda pop, its very sticky. With water it comes right off but try and clean it with solvent or oil--- no joy with that.

Make sure the ribbon cable is not upside down.

You might also have gotten bleach in the keyboard itself. so it might be shorting out.

Plug in a USB keyboard and boot with out the notebook one in place. Se if it will run normally that way. If it does then it could be the keyboard is bad.

Grabbed a USB keyboard from the trash.

noticed corrosion on the metal part of the keyboard. Bleach must have spilled somewhere in the membrane and shorted something out. Thanks, I will screw the keyboard back in place with the ribbon unplugged to keep out sand and dust. Everything else seems to work, mouse, even the original usb port.

Check on E bay for a used keyboard. Some times people part out notebooks instead of trashing them.

thats how i got one for my macbook.

He says he is good with it. The design is pretty good. one screw under the battery will pop off the front allowing full access to the keyboard so if he decides to replace it later its a 10 min job and 4 screws max.

Is the keyboard using so much power that the backlight can't get enough?