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Macbook Pro 13 A1502 (820-3536-A) Turn on ,no image no chime

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  • Macbook Pro 13 A1502 (820-3536-A) Turn on ,no image no chime

    Hi macbook have green then orange light on charger,turn on I mean fan spin ,but no chime ,no image (check with lights) no folder .PPVCC_S0_CPU is 1.74V should be 1.8V ? Inspecting under scope couldnt find any water damage

  • #2
    USB mouse lighting up?

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    • #3
      No light on usb mouse

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      • #4
        So a brain dead board.....Could be anything really. Look harder for corrosion or knocked off parts. The history on the board is the most important thing, must know!

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        • #5
          Is 1.74 V on PPVCC_S0_CPU mean maybe shorted somewhere on rail instead of 1.8V

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          • #6
            or could be the bios

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            • #7
              Fixed it was bios thx

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              • #8
                Uhm, did you fix the ME region?? You cannot just slap another BIOS on there...

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                • #9
                  Yeah its just for testing I put another bios and get chime and display ,today I will program the clear me bios and thats it .

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                  • #10
                    Use the original ME if the chip was original. Check if serial number matches from the bottom case. In doubt upload the BIOS here to be fixed.

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                    • #11
                      can u explain to me this repair? how can u fix the bios? the bios is in the SMC controller or in U6100? what is the ME region? u can send links too for deeper understanding, thx

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                      • #12
                        There is a lot you are asking for one post. This is how I learned my BIOS stuff. Here you go ielectron https://www.youtube.com/watch?v=rvrCSntnhyM I believe bios is around the 1hr mark or so!

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                        • #13
                          No I cannot explain this without writing a 1000 page essay on the topic. Most ME related stuff can be found with Google. When in doubt you can always upload BIOS on the forum to be fixed.

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                          • #14
                            in that video Louis heated up the U6100 bios chip to make it work again, then desoldered it, soldered it to a bios programmer TL866, heated up the chip again, read the bios, took another bios chip from a scrap board and programmed it with the original bios file, to sum up 2 hours of video than broke the board in half cause it did not work well that doesnt sound too complicated, i mean to deeply understand that it would take loads of time, but from a repair and technicians point of view that is rather quick repair. But why he could not fix that board eventually? was the bios file corrupted in the original? if so if i upload a bios file here how will it be fixed?

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                            • #15
                              Just a heads up, there are adapters you can connect to the JTAG header of the macbook which allows you to flash the bios from there. Saves a LOT of time and doesn't risk breaking the BIOS by desoldering it.

                              The site selling them is a bit questionable though, so I don't want to give free traffic by posting it publicly. Just google it or shoot me a PM if you're interested.

                              Anyways the ME region is the firmware for a separate part of the CPU (Kinda like a processor for your processor). If this firmware data is wrong/damaged/not matching the CPU it will show odd behaviour. You'll have to clear the 'used' ME region and place a clean firmware on there. Use google, it should be fairly easy if you take some time to read it through
                              Last edited by smiba; 10-10-2017, 05:13 AM.

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