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Dell U2413f no backlight

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    Dell U2413f no backlight

    Hi all, I have a Dell U2413f that has no backlight. Monitor can turn on and off normally without backlight. I will share the troubleshoot steps that I did and provide more information.

    Hence first thing that I did was probing the voltages on bareboard (Power board + display board ONLY *not connected to display panel, not sure is it call display board, pls let me know the correct term) and below are the voltages:

    Pin Volt (V)
    1 0
    2 NC [You can see there are no pin exist in the attached photo]
    3 0
    4 5
    5 24
    6 24
    7 11.8
    8 5
    9 5
    10 5
    11 0
    12 0
    13 3.3
    14 11.7
    15 11.7
    16 0

    Not sure if this info helps.

    [The following troubleshootings steps are done with display board only with no supply connected]
    Next with only display board, I notice that there exist some short circuits happens on the 3.3V related rail. Thus I first removed the LDO that has Vin from 3.3V and produce 2.3~2.4V, with ref des U101, PN EMP8090. The LDO input pin has short. Capacitor with ref des C105 & C102 connected to Vin was removed as well. Short still happens.

    After that U103 switching regulator with PN EML3180 that has 3.3Vout was removed as well. The capacitor on Vout with ref des C108 and C109 was removed as well. Short on 3.3 Rail still there.

    Next, I notice that audio driver have many pins short to ground as well! Pin 1,3,4[GND],9,10[GND],12,14. Thus I removed this IC as well however all these pin are still having short.

    Moving on, checked all zener diodes and notice ZD801 are having short to ground on both side thus was removed as well but things are not looking good.

    Hence now I was clueless and hope to seek help from you guys. What can I do next? I attached all the photo as well, do let me know if you have problem access the attachment, this is my first time posting attachment here.

    Thanks all in advance.
    Attached Files
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