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Alienware m15 r3 LA-J521P - no power

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    #1

    Alienware m15 r3 LA-J521P - no power

    Hi guys,

    I got this laptop with no power issue. What happens is when you plug it in, 20V stays on DC jack, but B+ gets power only for very short period of time and starts dropping. What I found out is if you isolate +5VALW by desoldering output jumpers voltage doesn't drop anymore, it stays around 12.5V on B+. Resistance on +5VALW coil was high, few hundreds of kiloohms on both sides of coil.

    I found short on PQB7, PQB8 and PQB10 between G1/S1 which was actually short on battery charger PUB1, and one of the double mosfets was shorted too so I replaced both of them. Unfortunately everything was same. Now there is no more short but nothing actually changed.

    Now funny part, I decided to change EC too because 3.3V regulator (PUS801) was only IC that was getting hot (around 35C), and EC was getting a bit hot, but just a bit. Now when I changed EC I lost voltage both +3VALW and +5VALW and PUS801 isn't getting hot at all. Voltage on B+ is constant again around 12.5V but that's probably because I miss 5VALW which was making issues at 1st place.

    Now my questions are:

    1. Is it possible that new EC was shipped faulty? (ENE KB9542GF) - very rare EC, only located on this exact model, that's why I'm bit suspicious. Markings are bit different shape than original.

    2. I guess it doesn't have to be programmed for basic power functions or I'm wrong?

    3. What voltages and signals does EC need to have to send 3V_EN and 5V_EN signals? Where should I look at?

    Thank you in advance for any suggestion or idea!
    Tags: None
    #2
    Re: Alienware m15 r3 LA-J521P - no power

    You need a programmed EC. the board will appear just like dead otherwise. From my short research It seems to have no connection to the SPI flash Chips on board, so likely not self programming or similar

    So place the old one back if possible. There is no indication it has failed and also embedded controller rarely fails at the late sequence. Usually It just becomes internal shorted at its VCC instead.

    Not sure what was going on in the DC-IN circuit, sounds also very unusual. However, 12.5V at B+ (+19VB) is to low. So there is still something wrong in DC-IN, except you're accidently measured the charging rail instead.

    What is the history of this device?

    I strongly suggest to not randomly continue like before from here. The issue might went worse.
    Last edited by Sephir0th; 01-19-2023, 05:31 PM.
    FairRepair on YouTube

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      #3
      Re: Alienware m15 r3 LA-J521P - no power

      12.5V at B+ may be correct if NVDC is involved. Yes the EC needs to be programmed with a SIO programmer like SVOD etc.

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        #4
        Re: Alienware m15 r3 LA-J521P - no power

        I got laptop like this, someone already attempted repairs. I believe one small capacitor near the thunderbolt controller was burned as it burned trace a bit too and input mosfet same thing.

        Problem is I'm idiot and when removing old EC I somehow damaged 2 pads on old controller so can't put it back.

        Other problem is I don't know how to program this new one as it's BGA and I believe (not near the laptop now), that keyboard is sort of USB bus so can't attach Vertyanov on it. Don't know how to do it?

        Also 12.5V was also strange to me, on battery terminal is 0.3V because I tested without battery.

        Any suggestion how to flash this new EC?

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          #5
          Re: Alienware m15 r3 LA-J521P - no power

          Programming a bga sio is bit tough. You need to first enable Jtag by moving a couple of resistors near sio(which can be figured out if schematic is available). Then you need to connect sio programmer with JTAG pins as per schematics. Not to discourage you but Its not that easy.

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            #6
            Can anybody tell me what's expected voltage for +NVVDD? My graphic card doesn't work, it's RTX 2070. I got 1.2V on VRAM and 0.813V on NVVDD. Only VBIOS I managed to find with same device ID is from Clevo laptop which is strange, and when I flash it laptop stays black just before loading windows. With that VBIOS my NVVDD voltage is 0.697V. Also not sure why it loses picture when it displays over Intel anyway, at least I think so. However, I was thinking if 0.813V was low too, maybe it needs to be higher.

            Anybody got a idea what to check?
            Attached Files

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              #7
              Did u ever managed to fix your issue, I have the same sio chip on my Alienware that needs to be reprogrammed

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