1. Ttm3

    OP Ttm3 GBAtemp Regular
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    This unit had a bad USB port. Changed that out and I had a short on pin 6 of m92t36. Remove m92 short is still there. Remove p13usb short is still there. Remove bga ic above audio chip short is still there. I removed all of the caps i could find on that circuit short is still there.

    What else could be pulling this thing down?
     
  2. FAST6191

    FAST6191 Techromancer
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    Any chance of some photos of the PCB in question?

    I would also be looking for any crushed layers.
     
  3. bombob

    bombob Advanced Member
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    Check usb pins continuity.

    Sent from my SM-N960U using Tapatalk
     
  4. Ttm3

    OP Ttm3 GBAtemp Regular
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  5. Ttm3

    OP Ttm3 GBAtemp Regular
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    Just retested everything and there is resistance of about 6-7 ohms to gnd on the 3v3 line. Any idea what else is driven by that circuit?
     
  6. Pintglass

    Pintglass GBAtemp Fan
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    Cpu
     
  7. Ttm3

    OP Ttm3 GBAtemp Regular
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    That's what I'm afraid of
     
  8. Pintglass

    Pintglass GBAtemp Fan
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    Check the usb data lines D+ and D- to see what resistance to ground you get on them.
     
  9. Ttm3

    OP Ttm3 GBAtemp Regular
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    5.19 ohms to ground & 4.89 ohms to ground
    .31 to each other
     
    Last edited by Ttm3, Jun 4, 2020
  10. Pintglass

    Pintglass GBAtemp Fan
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    I can’t remember what values they should be exactly but there normally a lot higher than that

    Check the esd protection device if it has one depending on version, if this is ok or not installed I’d say If your readings are correct your issue is cpu damage
     
    Last edited by Pintglass, Jun 4, 2020
  11. Ttm3

    OP Ttm3 GBAtemp Regular
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    Are you talking about the smd device on side a next to the USB port?
     
  12. Pintglass

    Pintglass GBAtemp Fan
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    The esd device is a 6 pin ic just above the 2 test points next to the fuse
     
    Last edited by Pintglass, Jun 4, 2020
  13. Ttm3

    OP Ttm3 GBAtemp Regular
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    I removed it and it made no difference
     
  14. Pintglass

    Pintglass GBAtemp Fan
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    Then it only leave's the SOC
     
  15. Ttm3

    OP Ttm3 GBAtemp Regular
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    I'll pull that off and see what I got
     
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