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Lenovo Legion 5 15ACH6H with possible short on +3VL.

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    Lenovo Legion 5 15ACH6H with possible short on +3VL.

    Hello!

    I am working on a Lenovo Legion 5 15ACH6H that will not take power when connected to the charger and will not turn on. The device was left in a car overnight when it got cold outside and no longer powers on. Inside the device was relatively clean and dust-free, and it did not have any immediate signs of liquid damage.

    The boardview files are available over at https://www.badcaps.net/forum/troubl...h-boot-problem. I am not sure of the etiquette of linking to files that are already posted to the site, so I will also post them here directly and leave the link to the original post. If there is an official stance on this, please let me know.

    So first thing first, I checked for any obvious physical damage to the board. I did not see any and was comfortable moving forward. I connected the charging cable to the motherboard and saw that PU6201 (RT6585C chip) was getting warm on the board via a thermal camera, and it was the only noticeable thing on the motherboard that was getting hot. I started to probe around and see where a short may come from, and capacitor PC6204 had a short on both ends. I looked at the component in the boardview file and noticed that it did not have a ground point on either side, so I decided to investigate a little further and noticed there was a jump point right next to it and removed the connection. In doing so, I removed the short on PC6204 and found the short was showing on the +3VL side. I then checked for everything connected to +3VL and found that it was only resistors. I checked all resistances and all of them were super close to where they were supposed to be (Most were 100kohms with the farthest out being 91kohms).

    Not sure what to do at this point to locate the issue and would appreciate any help. Maybe I am way off base and looking in the wrong spot, and if so, please let me know why. I am newish to this level of repair and still am learning so the why of things is really important for me to know too.

    Thank you all in advance for reading this and any help you may be able to provide!

    [Mod. Edit]
    Schematic and boardview -> https://www.badcaps.net/forum/troubl...562-schematics
    Reminder: rules and organization of this section
    https://www.badcaps.net/forum/showthread.php?t=117483
    Last edited by Vesko356; 01-13-2024, 10:54 AM. Reason: Attached schematic and boardview removed and replaced with link

    #2
    Ok, it appears that the short was removed when I removed the Lenovo IT8227E-192 chip. I saw there was a resistor with a short on both sides of PR127 (+3VL and DCIN_ATTACHED_EC) and DCIN_ATTACHED_EC was connected to the Lenovo IT8227E-192 chip. I removed it and all the shorts went away, I put it back and the shorts returned.

    Since it does appear that this is the issue, can I replace the chip with a new one with no issues or will it need to be programmed first?

    Comment


      #3
      The SIO needs to be programmed.

      Comment

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