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iPhone 6S Plus First Full short on DCPS then error 4013

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  • iPhone 6S Plus First Full short on DCPS then error 4013

    This iPhone arrived with a full short when connected to DCPS but the short was not on Bat_vcc it was located on the backlight anode line so I replaced the huge cap and the short was gone
    Now the phone turns on BUT, there was a bunch of small filters and caps missing below the LCD connector all replaced now
    The charging port FPC was smashed also replaced that

    So then the phone was stuck at apple logo and rebooting and a DFU restore only leads to 4013 just at the moment the progress bar shows it reboots to recovery and error 4013 appears.
    I tried tristar as well just to rule that out.

  • #2
    I’d look for signs of excess heat, bridges at filters, swapping a filter for a cap etc. go back and erase the last things you did looking closely for faults

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    • #3
      Thanks for your reply Jessa,

      I did not use heat at any of the steps I took, only when replacing tristar and the charging fpc and I did check that again but I had the error before and after, I left the small caps off below the connector only soldered the missing filters, and the big anode cap was soldered using tweezers as well.

      I'm trying to find heat on the board but the recovery screen does not generate much


      Edit: I jusr noticed that bat_vcc is at 399 instead of 450 not sure if this is enough to casue a problem but tried removing the active diode to isolate and replacing tigris also removed the 2 big caps on the line and still 399
      Last edited by LastDeuS; 01-11-2018, 11:10 PM.

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      • #4
        are you sure that you are getting pp3v0 at tristar? This sounds like an inability of the CPU to talk to NAND or understand NAND, possibly because NAND formatting has been damaged-- not a short circuit. If the problem is not a short circuit then it won't produce heat. This is a data line or software problems and those are pretty big rabbit holes. You could look for any relationship between data line communication and places that you've worked---such as backlight driver and just try to eliminate variables.

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        • #5
          Originally posted by Jessa_the_Professa View Post
          are you sure that you are getting pp3v0 at tristar? This sounds like an inability of the CPU to talk to NAND or understand NAND, possibly because NAND formatting has been damaged-- not a short circuit. If the problem is not a short circuit then it won't produce heat. This is a data line or software problems and those are pretty big rabbit holes. You could look for any relationship between data line communication and places that you've worked---such as backlight driver and just try to eliminate variables.
          Sorry Jessa I'm not sure how to proceed when it comes to "data line communication" I don't know what to look for on the schematic if you were referring to the i2c2 lines I did check those in diode mode and every other backlight driver line as well.
          At this point the only thing I could do was test almost every voltage on this board related or not and I can safely say that every voltage is present.


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          • #6
            The way I would look at data lines is these are the lines that send information from one device to another. Mostly in both direction. These are not the the enable lines, clock lines etc but In this situation the data would be the software information from the CPU to the NAND and possibly from the NAND to the CPU

            So for example if one of the data lines was open circuited then the incorrect information would be send to the device. I not know how many date lines are there but say they were 8 data lines (this is a byte) and then each word is made up of 8 bits.

            Then for example if a correct byte (8 bits) is 1111000.and if the fourth bit is open circuit . An open circuit will produce a hight (1). So now the information is 1111100. This is now incorrect information send to the NAND

            In digital communication data is transmit in one's and zeros



            Try and compare with a good board. The faulty bit if open circuit will always be hight while a good board would be going from hight to low


            The best way to see data lines is by a oscilloscope. and do a compassion between a good board and the faulty board




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            • #7
              That is why data line communication is a pretty big rabbit hole. There is no way to efficiently find a solution. There will be no physical damage and no way to know what communication is either being garbled or if the problem is that the NAND has lost its formatting and you don’t have any line level communication faults at all.

              In an ideal world there would be a way to listen in on data line communication through a debug port and be able to reformat the NAND or at least have a way to compare the ones and zeros going through the lines with a good phone and create a report on what line was garbled or missing. But we don’t have a way to do that.

              so what you’re left with is:
              1–Remove backlight driver and be sure that you don’t have a loose or missing resistor such as the ones in the row above backlight driver and try to restore.
              2–confirm that you don’t have a solvable power problem at a data chip like tristar—is tristar still plugged into the wall? Is it getting its 3v0?
              3–buy a NAND reformatter for the iPhone, remove NAND and reformat it, then reball and replace
              4–after that—craziness. Remove cpu and check all the hundreds of pads for a diode mode difference and look for sponginess on any of those pads and add any jumpers, etc.

              If this were my board I’d do number 1 and 2, and then say “not feasible to repair”. I’d do number 3 if I had the reprogrammer. And screw number 4!

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