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Repair information and guides for the Apple iPhone 5s that was announced on September 10, 2013. Model: A1533, A1453, A1457, A1528, A1530, A1518

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Board Repair - No Backlight, display is working

Hello, i'm getting to a no end and i will try to add as much information as i can.

I have an iPhone 5S to repair, the start problem was no touch. The board was water damage sticker in red so i have clean the board in a ultrasonic cleaner. After that as LCD replacement didn't help i've reflow the touch IC U12, which solve the touch problem, but after a short time backlight gone [I never connect stuff with battery in], it have image, touch continue to work as the iPhone. So i start to test stuff, all filters, inductor, caps etc are good, i have two dead boards that i use to gather the components, and i have tried to swap the L3, D1, C131, U23, U3. The result is the same, phone work but no backlight... The Connectors are good, LCD is good so i reach a end without a solution.

C329: 6V

C52: 5V

C330: 5V

C103_RF: 5V

C369: 0V

C131: 4.2V (VIN) (Yes i know it should be 16V but i can't find why)

PP_LCM_BL_CAT1_CONN: 0.6V +/-

PP_LCM_BL_CAT2_CONN: 3.2V +/-

PP_LCM_BL_ANODE_CONN: I don't renember the value but is not normal...

Again FL's seens OK and none is open, voltage reach there.

May i be out of luck and the U23 i took from other boards are damaged too?

Any recommendations?

Answer this question I have this problem too

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Check the LEDs themselves and make sure that the cable that connects the backlight to the motherboard is not severed in any way whatsoever. If you have a microscope, use it to make sure that none of the cable is bent or broken. If the backlight cable is ok, then double check your soldering and make sure that you do not have a bridged connection.

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As i told on main post, i tried a new LCD, both LCDs are good as i test them on other iPhone. I didn-t solder anything, just reflow the touch ic and perform all others checks as i mention above

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Tiago will be eternally grateful.
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