iPod Touch 4 Backlight diagnostics testing help (3.6v or 5v over pins)
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I have an ipod touch 4th gen, it has been dropped and the backlight no longer works(screen still works, can be seen in bright light, and digitizer works fine to and I can play my music etc etc.) so I've done some tests to try and work out why the backlight isn't working before I assume its the LCD/Digitizer unit and waste money replacing it.
I've stripped the unit and removed the LCD/Digitizer assembly.
on the back of LCD connector there is a mirrored plate, and next to that plate (under some yellow insulation tape) there are 2 pins, these are the pins in question.
They are placed right at the base of the thin 2 wire ribbon that attaches to the LCD's LED backlight so...
1. I'm thinking these are the backlight power supply points, can anyone confirm?
2. Ive checked it with my multimeter = screen off 3.6v = screen on 3.6v (- i think shakey hands so only 75% sure) can anyone confirm if this is correct?
I've disconnected it and put 3.6v and 5v in both polarities over these 2 pins, and the backlight doesn't light up, is this normal behavior, or is my backlight faulty or do I need more than 5 volts??.
I'm trying to figure out if I need to replace the IC that controls the backlight (<$5 from the states), the coil that sits between the IC and backlight, ( again <$5 from the states) OR the expensive LCD,Digitizer assembly (which will no doubt be a sub quality Chinese knock off, and might not work anyway!)
^ OR a combination of the above 3 items.
any help would be cool, if someone could test a known working unit for voltage etc (I had my brightness on full, and auto off).
It would be a real help to me, and the repair community if we could start working out the LCD pinout, or at least the backlight pinout
Thank you all very much for reading, please don't answer, unless you have an answer :) lets keep this thread clean!
Thank you very much for reading all that =D