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Asus R511L - X555LI won't power on

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    #1

    Asus R511L - X555LI won't power on

    Hi everyone,

    I've been lurking on this forum for quite some time now, but I have a hard time wrapping my head around some stuff you might find basic.

    I have an Asus R511L laptop that was most likely subject to a surge (owner told me that it started developing problems after a storm). Upon inspection, looks like some components got a tad bit hot.

    https://imgur.com/2jk7Ngh

    I was able to find a boardview and a repair guide for the Asus X555LD 3.1 (boards seems to be the same, at least those numbers are written on the smaller SATA and USB/AUDIO boards), but no schematic, so it was kind of hard to find the values for those components, but I managed to order new caps & resistors, I cleaned up that part of the board and soldered new stuff.

    As soon as I plug the AC adaptor in, I can hear a high pitched sound (like a dying capacitor in an LCD screen) and a click every second. When it clicks, 2 LEDs flash briefly. I don't see any obviously bad cap.

    This happens even with nothing connected (no keyboard, sata, LCD, ... nothing, just the mainboard). If I press the power button, nothing happens, but if I keep pushing it for ~10 seconds, the clicking stops, but I still can't boot.

    I've tested some voltages : AC_BAT_SYS is good at 19V, +3VA is good and stable at 3.3V, so is +3VA_EC, +5VA oscillates a tiny bit (maybe 0.2V drop when it clicks).
    +3VA_DSW seems to be the culprit because it drops to 0V each second.

    The problem I have is that I have no schematic to trace where +3VA_DSW is coming from and identifying the components responsible.

    My guess is a short to ground somewhere, but I didn't really understand how to find one using by testing the coils to gnd resistance. I've found a couple of points with a low resistance to ground, but working only with the boardview, it's kind of hard to figure out what components are on that side of the coil.

    Do you guys have any advice ? Maybe a schematic for this board (or one close enough) ?
    Last edited by melkalehun; 03-11-2018, 01:31 PM. Reason: Sorry, I made a mistake in the post title, it's a X555LD board, not LI, if a mod could change it ?
    Tags: None
    #2
    Re: Asus R511L - X555LI won't power on

    This looks like liquid damage on the picture, not storm damage. There would not be green and white stuff otherwise.

    Asus schematics are usually not available. You may get some inspiration with the UX31A schematics but your board will still be quite different so you will have to rely on the boardview.
    The boardview should tell you all you need to know for now.

    The issue you describe seems like a power rail shorted (S3 or S0).
    Locate all the coils and check the resistance to between one end of the coil and ground (screwhole). Multimeter in resistance (Ω) mode, one probe on one lead of the coil, the other probe on a screwhole. If it's not an autoranging multimeter, use the 200 ohms ranges.
    Report value of resistance for all coils which show a value lower than a few hundred ohms. Identify the coil and the line they are on using the boardview.
    Some of them are normal (CPU VCore for example) so we will need to filter out later what's interesting.
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment

      #3
      Re: Asus R511L - X555LI won't power on

      Hey Piernov, thanks for the input ! And an awful lot of thanks for the work you guys are doing with OpenBoardView !

      I tought about water damage too, but I chose to believe what the owner told me. Fool me once, I guess There are a couple of other spots with a tad bit of the green / white stuff, I'll try to investigate those areas, but it also looks like there was a spark flying at some point : a pin on the LVDS connector is all darkened

      Here are the values for the coils and ferrite beads on this board. The 3 ferrites (PL6000 / PL6001 / PL6002) have been changed with new ones, they were in the damaged area shown in the pic.

      +VCCIN on this board goes on the CPU, so I guess PL8003 is ok.

      Code:
      PL6000/PL6001/PL6002 - Ferrite Bead 0603
1 - +V_DCJACK - 150kΩ
2 - A/D_DOCK_IN - 147kΩ

PL8003
1 - P_VCCIN_LX1_30 - 64Ω
2 - +VCCIN - 64Ω

PL8100
1 - +3VADSWO - 2.05kΩ
2 - P_3VADSW_LX_30 - 2.05kΩ

PL8101
1 - P_5VSUS_LX_30 - 20.6kΩ
2 - +5VSUSO - 20.75kΩ

PL8200
1 - +1.05VSUSO - 360Ω
2 - P_+1.05VSUS_LX_S - 360Ω

PL8301
1 - P_DDR_1.35V_PHASE_30 - 560Ω
2 - +1.35V - 560Ω

PL8501
1 - P_NVDD_LX1_S - 23Ω
2 - +NVDD - 23Ω

PL8502
1 - P_NVDD_LX2_S - 22.5Ω
2 - +NVDD - 22.5Ω

PL8801
1 - P_CHG_LX_30 - 157kΩ
2 - P_CHR_RSENS_SHAPE - 156kΩ

      Comment

        #4
        Re: Asus R511L - X555LI won't power on

        This message is just to bump up the thread. Anyone has any advice on how to tackle this board ?

        Comment

          #5
          Re: Asus R511L - X555LI won't power on

          Did you solve or fixed it?

          Comment

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