Nov 142012
 
iPad 4R7 Backlight coil

Location of iPad 4R7 backlight coil

If you have a dim or dark screen on  your iPad device, then there is a possibility that the coil that fires up the backlight is faulty or burnt out.  In order to test this you will need to disassemble  your iPad 2 and access the 4R7 coil to see if this is the cause of the failure.  Now if you have an iPhone 4 it has a 6R8 Coil  you will need to test it to determine if this is the cause of your faulty iPhone 4 screen.  Any multi-meter should do the trick.  see the photo to identify the 4R7 Coil Location.

Feel free to comment below, or link to photos of your failed backlight coils.  I would be glad to have some extra photos showing my readers personal success stories.

This coil is susceptible to failure if your iPad screen is damaged or broken in a fall.  If the screen shorts its power connection during its replacement it will cause a surge in the 4R7 coil resulting in failure.  The only way to resolve this issue is to then either replace the coil. Or the logic board on which it resides.

I have also included a photo of the iPad mini backlight location.

Oct 222011
 

If you have a lenovo laptop with a Dim Backlight, and a LED Screen, the cause is most likely a blown fuse on the motherboard.  In most cases newer laptops, are using an LED’s instead of CCFL‘s, which negates the need of an Invertor, so now manufacturers are placing a fuse on the motherboard, to protect the screen from surges.  However sometimes a momentary problem can blow this fuse, and kill power to the screen rendering the computer unusable.  however with a little time, and a lot of heat (soldering) you can replace this puppy.  Jump over to this post to get the link for the FUSE you need.

SMD FUSE Sources