Logic board repair help needed please please

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • lcdcaps1
    Badcaps Veteran
    • Oct 2011
    • 322

    #1

    Logic board repair help needed please please

    Hi

    I am in need for some help to fix my old Macbook Pro ( 17", A1229, 2.ghz)

    The Macbook pro was working fine until recently when I had to check the fans and sensors due to AHT reporting one was not working.
    So I opened it up and done some cleaning and went to boot it up which it did but got the black screen, no chime, solid white light on the latch in the front, no back light but fans turn on and hard drive spins up.
    I done the PRAM and SMC reset but not no luck

    I was puzzled so I done some research and everyone suggested do a reflow, so i followed the ifixit guide but no luck,

    I put everything back together and to find a weird problem that i have to press the power button 3 times or more to get it to start. Everytime I press I see the fans move a little and hear the hard drive click but doesnt start up
    after few more presses it does start up but with same symptoms, black screen, no back light, solid white light on latch, no chime.

    I took the top case off and tried starting macbook by jumping power on pads.same thing have to keep pressing the pads a few times before it starts, Also before the SYS RST pads used to restart the laptop but that does not work neither

    I checked the RAM, one by one in each slot, the charger.
    Charger has green light


    Same thing happens when powered by battery
    I downloaded the schematic diagram, found via a google search and started measuring and following the flow of power as seen on page 3. Measuring voltages on all the power lines but I am hoping you can help me on what points to measure and if it requires me to replacing components then I can do that, I have a multimeter and access to a oscilloscope

    I really don't think it is anything major, I think it is a capacitor, resistor or chip that has gone.
    I know these models had the nvidia problem and people repair them but I want to repair it myself with your help
    Apple store do not repair these any more.

    I was hoping if someone can help me please
    I will appreciate it so much

    I look forward to your reply

    Many Thanks
    Kind Regards
  • angel-boy
    Badcaps Veteran
    • Jan 2013
    • 550
    • Romania

    #2
    Re: Logic board repair help needed please please

    mainboard type number ?

    Comment

    • lcdcaps1
      Badcaps Veteran
      • Oct 2011
      • 322

      #3
      Re: Logic board repair help needed please please

      HI
      It is 820-2132-A
      If anyone has a board view for this It will be really appreciated as well please

      Thanks for the reply
      So much
      Thanks in advance

      Comment

      • dellxps15
        Badcaps Legend
        • Feb 2014
        • 1591
        • italy

        #4
        Re: Logic board repair help needed please please

        inspect the board for a simbol on mainboard for turn on and off like the one on remote for tv ecc ecc. when u find it post picture.

        Comment

        • lcdcaps1
          Badcaps Veteran
          • Oct 2011
          • 322

          #5
          Re: Logic board repair help needed please please

          hi
          what do you mean
          the pads

          Comment

          • dellxps15
            Badcaps Legend
            • Feb 2014
            • 1591
            • italy

            #6
            Re: Logic board repair help needed please please

            Originally posted by lcdcaps1
            hi
            what do you mean
            the pads
            yes 2 pads with that symbol near them.

            Comment

            • lcdcaps1
              Badcaps Veteran
              • Oct 2011
              • 322

              #7
              Re: Logic board repair help needed please please

              there are two pads and has PWR ON
              also another two that have SYS RST

              Comment

              • dellxps15
                Badcaps Legend
                • Feb 2014
                • 1591
                • italy

                #8
                Re: Logic board repair help needed please please

                post picture on this thread. attach them

                Comment

                • lcdcaps1
                  Badcaps Veteran
                  • Oct 2011
                  • 322

                  #9
                  Re: Logic board repair help needed please please

                  Attached are pics of PWR ON AND SYS RST PADS
                  If any one has the board view file for the 820-2132-A motherboard I Will be so grateful if it can be shared or uploaded or sent by PM please. Many Thanks in advance
                  Attached Files

                  Comment

                  • dellxps15
                    Badcaps Legend
                    • Feb 2014
                    • 1591
                    • italy

                    #10
                    Re: Logic board repair help needed please please

                    short 2 power on pads and see if macbook power on like normal. if it power on, but no display, check if cpu and chipset and gpu get hot.

                    Comment

                    • lcdcaps1
                      Badcaps Veteran
                      • Oct 2011
                      • 322

                      #11
                      Re: Logic board repair help needed please please

                      Hi
                      As stated in my first post I was jumping these pads and there is not reaction.
                      No fans, no chimes, no back light, no video (black screen), solid white light on latch.

                      The sys rst pads does not do anything neither
                      I don not think the cpu and gpu get hot

                      Comment

                      • dellxps15
                        Badcaps Legend
                        • Feb 2014
                        • 1591
                        • italy

                        #12
                        Re: Logic board repair help needed please please

                        if it didnt power on, checl for 3.3volt if it is present . tipically it is a tps51125 check for that voltage on the inductor near it.

                        Comment

                        • lcdcaps1
                          Badcaps Veteran
                          • Oct 2011
                          • 322

                          #13
                          Re: Logic board repair help needed please please

                          I will Check and.report back
                          Can you confirm.which inductor I should test. Will there only be.one on the 3.3v line (

                          Comment

                          • wibble
                            Member
                            • Jan 2011
                            • 31

                            #14
                            Re: Logic board repair help needed please please

                            When you say you reflowed the board what exactly did you do to it?
                            It sounds like there may be a problem with the SMC. This is a microprocessor which manages various power states, I believe it also deals with sensor outputs. It is a 3mm ball grid array I believe so the usual caveats with BGA apply. I believe it is U4900. You can check you have stable G3h which is 3.42V then you can also check the input to SMC which is 3V or 3.3V.

                            Comment

                            • lcdcaps1
                              Badcaps Veteran
                              • Oct 2011
                              • 322

                              #15
                              Re: Logic board repair help needed please please

                              hi
                              can i use the test points to test the smc
                              also i cannot find the inductor to test and cannot find tps51125
                              please help
                              thanks so much

                              Comment

                              • lcdcaps1
                                Badcaps Veteran
                                • Oct 2011
                                • 322

                                #16
                                Re: Logic board repair help needed please please

                                HI
                                Sorry it has taken me so long to reply
                                I have an update
                                The Macbook pro now turns on for a few seconds, the hard drive spins and fan starts and then off by its self if when I plug in the charger. If only the charger is connected it will not turn on by jumping the pads but when I plug in the battery only the power button works first time press.

                                I am more confused on whats going on
                                please can some one help me

                                Thanks
                                Waiting for everyones reply

                                Comment

                                • dellxps15
                                  Badcaps Legend
                                  • Feb 2014
                                  • 1591
                                  • italy

                                  #17
                                  Re: Logic board repair help needed please please

                                  probably a short on dcin line. we need schematic and board view to help u out. i assume one of 2 fets that supply 12.5 volt are shorted. post picture of board bottom and low picture in high quality.

                                  Comment

                                  • lcdcaps1
                                    Badcaps Veteran
                                    • Oct 2011
                                    • 322

                                    #18
                                    Re: Logic board repair help needed please please

                                    HI

                                    Thanks for the reply
                                    You can view the schematic here


                                    I do not have the board view.
                                    Can you tell me which mosfets I need to check. Also is it is a case of just checking voltage measurements according to the schematic.

                                    Comment

                                    • dellxps15
                                      Badcaps Legend
                                      • Feb 2014
                                      • 1591
                                      • italy

                                      #19
                                      Re: Logic board repair help needed please please

                                      L7900 check if it's shorted.
                                      check voltage u7900 pin 1 and 25.

                                      Comment

                                      • lcdcaps1
                                        Badcaps Veteran
                                        • Oct 2011
                                        • 322

                                        #20
                                        Re: Logic board repair help needed please please

                                        Will check and report back
                                        Thanks

                                        Comment

                                        Related Topics

                                        Collapse

                                        • howardc64
                                          A1312 (27” iMac 2009-2011) A1407 (Thunderbolt Display) A1316 (Cinema Display) Display Black Screen Repair
                                          by howardc64
                                          Problem

                                          This is an LG edge LED lit LCD Display. The LEDs are on the bottom edge of the display. There are 2 bars (left and right) Each bar has many LEDs and a 6 pin connector. Each pin drive several LEDs thus is the highest current flow / heat junction. The weak lead free solder gradually fails with thermal expansion/contraction cycling and increases resistance. PSU will compensate up to a point, then when the current is too high, PSU just shut down the backlight causing a dark display. I have even seen one which the connector just fell off as solder points became completely detached....
                                          08-04-2024, 10:36 PM
                                        • m1ch43lzm
                                          HP Pavilion 15-eh Board DAG7HAMB8F0 - CPU throttling to 0.4GHz (PROCHOT_EXT) and black screen
                                          by m1ch43lzm
                                          Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
                                          Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic...
                                          05-12-2025, 08:37 PM
                                        • Yanleb
                                          LG 60PK550 Logic Control Board EBR63450301
                                          by Yanleb
                                          Hi all, I just want to share the repair of my 60PK550-UA TV set.

                                          The TV set was powering on, just no image. After verification, nothing wrong on the YSus or ZSus boards. Nothing wrong on the main board either.

                                          But I noticed that the LED was not flashing on the Logic Control Board. This is an EBR63450301. The LED is supposed to flash even with all the flat cables disconnected, with only the power cable attached.

                                          All the voltages measured at the electrolytic capacitors on the board were good. From top left to bottom right:
                                          C57: 3.30V
                                          C61:...
                                          07-20-2023, 12:38 AM
                                        • boosti45
                                          MacBook logic board 820–01949 repair help needed please
                                          by boosti45
                                          I have a 2020 MacBook Pro touch bar 13 inch with the board 820–01949 that I'm currently working on that is my personal computer and long story short quit working got 5 V and no amps found out the computer was in DFU mode and I finally got it to go through and get on, and it would make it about halfway through, and then it would freeze while reviving so I would end up turning it off and starting over and on the third or fourth attempt I decided just to let it sit there and be frozen and see if it eventually finished and I came back like 15 minutes later and the computer was off and so I ended...
                                          09-12-2024, 12:32 AM
                                        • korben_dallas
                                          Will I have a bricked logic board after reflow of the GPU v-core U8900 chip on my Mid-2012 15" Retina Macbook pro?
                                          by korben_dallas
                                          Hi everyone! I'm trying to fix my black screen / failed U8900 GPU v-core on my Mid-2012 Macbook Pro 15" Retinaby doing a rework/reflow of the chip (once I determine that's the real issue; but it likely is).

                                          I've been disabling the GPU in NVRAM for a few years... but it's just time for a better solution.

                                          I'm new to soldering but the only feasible way to fix this issue is to do something myself.

                                          MY QUESTION:
                                          I've been seeing some people (on this forum mostly) run into issues with the logic board needing a serial number or it being deactivated (?)...
                                          02-14-2024, 12:23 AM
                                        • Loading...
                                        • No more items.
                                        Working...