Most likely cause of iPhone backlight malfunction?
My phone is pretty old now and so naturally it is not without its flaws. The vibrate had stopped working and the power button was nigh on impossible to depress. When I opened it up to repair these issues I seem to have inadvertently caused the backlight to die.
As it turns out, that blob of glue in the top left hand corner had come loose and was no longer holding apart the headphone jack and volume ribbons. Ironically a screw which had come loose from the board had taken its place and prevented a short. Hence when I returned this screw to its rightful place and put the phone back together... it failed to turn on and simply got very hot, very quickly.
This happened twice before I identified the culprit and patched it with insulation tape. I was quick to open up the phone and make sure it was disconnected fast to avoid too much damage from the short. However now it appears my backlight will not function. All else is working fine however. I have taken a look at the 6r8 coil responsible for the light circuit but see no signs of damage. I am unclear however as to whether this ever looks damaged or burnt out from the outside.
It is also possible that the short simply stopped because the coil burnt out and my solution was coincidental. There is an issue with the top two pins on the top row of the LCD ribbon house also being slightly out of line. It has been like this for two years however and caused no problems.
My questions are therefore:
Does the 6r8 coil look damaged when it is... damaged?
Is running the phone without the backlight likely to cause further issues (if the coil has blown)?
What other issues could cause this?