Recent content by Narek

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    iMac 21,5" 2019 820-01237 clean BIOS request

    Or maybe somebody with access to medusa could clean ME region in my BIOS? EDIT: Can't paste link with file here...
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    iMac 21,5" 2019 820-01237 clean BIOS request

    Could somebody share a clean BIOS for 820-01237 please? I've downloaded several ones and they don't work or they are 16MB instead 8MB...
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    820-01949 not charging

    Update for this board... So I was working on another board - 820-02020 with very similar issue. After replacing one of the USB-C controllers board was not switching to 20V an not charging battery. Trying different controllers I found out, that controller had to be pulled from M1 board, in my...
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    820-01949 not charging

    No, it doesn't turn on without battery, but I think it's typical for these models - they need battery to turn on. All USB-C ports behave the same and LDOs on all USB-C controllers are the same with good readings.
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    820-01949 not charging

    Board has slight liquid damage on U3100 chip (photo). I’ve replaced the chip itself (CD3217B12) and other SMD components around, checked resistances and traces - all fine. Computer is turning on and working, but does not charge the battery (doesn’t even detect charger connected). With battery...
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    820-00928 internal display works only with external display connected

    Internal diagnostics doesn't show any errors. I will test it with mentioned windows or linux. But just from curiosity - maybe there is a way to trick the board (on the board side), that external display is connected?
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    820-00928 internal display works only with external display connected

    So this case is really weird. I got an 820-00928 after slight water damage around J8500 and U8500/U8501. I have replaced U8500/U8501, J8500 and eDP connector on LCD side. Also put new eDP flex. I've found out, that EDP_AUXCH_C_P line is shorted, so I've replaced U9850. Now computer turns on...
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    820-02016 completely dead

    Yes, I know, that RAM is soldered on processor. Just wondering if I can take the chips from donor and solder to this board p&p? If I apply voltage to this rail one of the RAM chips starts to slightly warm up and board takes ~0,080A compared to 0,005A on working board.
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    820-02016 completely dead

    Working on M1 Air with 820-02016 board. Customer turned it off in the evening and in the morning couln'd turn it back on. Board has no signs of damages, corrosion or so. It doesn't switch to 20V, stuck at 5V and fluctuating between 0,038A to 0,13A. Trackpad doesn't click, can't get into DFU...
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    820-01958 brain dead

    So MB needs new board. Thanks!
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    820-01958 brain dead

    I got an 820-01958 after liqiud spill. Motherboard was not affected at all, no spots or corrosion, only audio board had some corrosion. Anyway board was completely dead. I have found out, that PP1V8_G3S is shorted in U6400. I have replaced that chip and short is gone. Board switches to 20V...
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    820-00281 no SUS voltages

    Ok, with this BIOS everything works, problem solved. Thank you @2informaticos for your help.
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    820-00281 no SUS voltages

    So I have replaced PCH, both PP1V0_SUS / PP1V_PCH_REG_R lines are now present, nothing shorted. Board starts, CPU VCORE is present, all S0 voltages too but there is no video, no chime, just clicking trackpad. Board takes ~1A from charger. I have already tried new bios found on this forum, but it...
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    820-00281 no SUS voltages

    Yes, I'm going to replace PCH and clean ME region in BIOS.
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    820-00281 no SUS voltages

    After I have posted this thread I have discovered, that PP1V0_SUS / PP1V_PCH_REG_R are shorted - 0,000V in diode mode and 0,001 Ohm. If I inject 1V, board takes ~0,3 - 0,5A but nothing really gets warm, even PCH. I have lifted up L8000 and short appers to be at PCH side.
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