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Power adapter from Apple Time Capsule - 0V at output

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    Power adapter from Apple Time Capsule - 0V at output

    Hello! I'm not very experienced technician… Just trying to repair power adapter from Time Capsule. Maybe anybody have experience in these units?

    This power adapter must output 5V and 12V. But now it outputs 0. I made full recap. Also, I checked voltage at output diode bridge - it's DC 220 V, so diode bridge is working.

    I don't have scheme so I don't know what to check next… So I'm ask maybe anybody know what the most possible can be broken (if no capacitors) in such power adapters. Manufacturer - Flextronics.

    Some photo attached. Thanks for any help!
    Attached Files

    #2
    Re: Power adapter from Apple Time Capsule - 0V at output

    Please can you update your profile with country and mains voltage.
    220DC doesnt sound correct
    Please upload pictures using attachment function when ask for help on the repair
    http://www.badcaps.net/forum/showthread.php?t=39740

    Comment


      #3
      Re: Power adapter from Apple Time Capsule - 0V at output

      220V DC at the output of the bridge rectifier would be correct for 220V AC input. I would desolder the main switching transistor and check that next. It should be the device bolted to the aluminum heatsink.

      Comment


        #4
        Re: Power adapter from Apple Time Capsule - 0V at output

        220VAC in put to the bridge, the output will be (220VAC x 1.414) - two Diodes Vf drop, you should have about 310VDC on the main filter cap (measured directly at the two legs of the cap.
        So verify the AC and DC voltage readings again.
        Last edited by budm; 02-22-2014, 10:04 PM.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment


          #5
          Re: Power adapter from Apple Time Capsule - 0V at output

          Thanks all, yes, the output on the main filter cap is about 310 VDC (measured directly at the two legs of the cap).

          The input is 220VAC, like in any country in Europe.

          370forlife, is it possible to check main switching transistor, if I only have simple tester? I've heard this maybe FET transistor, so I afraid to damage it during testing.

          Comment


            #6
            Re: Power adapter from Apple Time Capsule - 0V at output

            Post good clear straight shots of both top and bottom side of the board, it can be as simple as bad start up cap (the small electrolytics cap next to those two 450VDC filter cap) in the primary side.
            The power MOSFET mounted on the heat sink on the primary will usually failed shorted circuits which will cause the main fuse to blow, but since you are getting the DC on the main cap, the main fuse is OK.
            You can try heating that start up with hair dryer to see if the circuit will start up if the cap is not too far gone, you can also measure the DC voltage at the two legs of the startup cap, just be real careful since you will be working in the deadly primary side of the circuit.
            Last edited by budm; 02-23-2014, 02:27 PM.
            Never stop learning
            Basic LCD TV and Monitor troubleshooting guides.
            http://www.badcaps.net/forum/showthr...956#post305956

            Voltage Regulator (LDO) testing:
            http://www.badcaps.net/forum/showthr...999#post300999

            Inverter testing using old CFL:
            http://www.badcaps.net/forum/showthr...er+testing+cfl

            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
            http://s807.photobucket.com/user/budm/library/

            TV Factory reset codes listing:
            http://www.badcaps.net/forum/showthread.php?t=24809

            Comment


              #7
              Re: Power adapter from Apple Time Capsule - 0V at output

              I have made good (good, not perfect) quality photos of board. Also, I added some comments. Attach them here.

              As I understand, I need to try heat up small electrolytic cap (in red circle on my picture) during start up to see if the board will work under heating?
              Attached Files

              Comment


                #8
                Re: Power adapter from Apple Time Capsule - 0V at output

                That is the start up cap, I would replace it (try heating it to see if the power supply will start up), that device mounted on the heat sink is the power MOSFET which drives that yellow power transformer.
                Also take the DC voltage reading right at the two legs of that start up cap.
                P/N of that SMPS IC U6?
                Last edited by budm; 02-24-2014, 12:29 PM.
                Never stop learning
                Basic LCD TV and Monitor troubleshooting guides.
                http://www.badcaps.net/forum/showthr...956#post305956

                Voltage Regulator (LDO) testing:
                http://www.badcaps.net/forum/showthr...999#post300999

                Inverter testing using old CFL:
                http://www.badcaps.net/forum/showthr...er+testing+cfl

                Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                http://s807.photobucket.com/user/budm/library/

                TV Factory reset codes listing:
                http://www.badcaps.net/forum/showthread.php?t=24809

                Comment


                  #9
                  Re: Power adapter from Apple Time Capsule - 0V at output

                  I tried to measure voltage on start up cap, it changes between 5 and 15V, like on the video (scale on this video is 50V): http://www.youtube.com/watch?v=aoSz1As3iI4

                  Also, I tried to heat up this cap, but this not help. I will replace it on weekend, when I'll be at radio-parts market.

                  P/N of SMPS IC U6: 1271AH PASM

                  Thanks)

                  Comment


                    #10
                    Re: Power adapter from Apple Time Capsule - 0V at output

                    Try to get a low esr cap panasonic fr fm or fc or nichicon or rubicon equivalent - are any of those available at reasonable cost?
                    Please upload pictures using attachment function when ask for help on the repair
                    http://www.badcaps.net/forum/showthread.php?t=39740

                    Comment


                      #11
                      Re: Power adapter from Apple Time Capsule - 0V at output

                      Originally posted by selldoor View Post
                      Try to get a low esr cap panasonic fr fm or fc or nichicon or rubicon equivalent - are any of those available at reasonable cost?
                      We have only "CapXon" on market, so I'll buy what found. Cost for electrolytic capacitors is more than reliable on our market. From 10-20 cents for small caps to $2 for very big.

                      Comment


                        #12
                        Re: Power adapter from Apple Time Capsule - 0V at output

                        I replaced start up cap, but this not helped. So, all electrolytic caps are new at the moment.

                        Now, I think to look at PWM controller NCP1271AH, this is 65kHz PWM, I found datasheed for it (attached if someone in future will look for it). I bought old used simple oscilloscope (will arrive at weekend), so I can post more info after inspection with oscilloscope

                        If anybody have something to say - please post, I do further investigation at weekend and post results.

                        If anybody have simple block diagram which explains principle of operation of Switching Power Supply please post.

                        Thanks all for participation!
                        Attached Files

                        Comment


                          #13
                          Re: Power adapter from Apple Time Capsule - 0V at output

                          Since you will be working in the primary (HOT) side of the circuit, make sure to plug this board into the Isolation transformer before attaching your scope probes to the board.
                          Trying the IC will be a good idea.
                          Never stop learning
                          Basic LCD TV and Monitor troubleshooting guides.
                          http://www.badcaps.net/forum/showthr...956#post305956

                          Voltage Regulator (LDO) testing:
                          http://www.badcaps.net/forum/showthr...999#post300999

                          Inverter testing using old CFL:
                          http://www.badcaps.net/forum/showthr...er+testing+cfl

                          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                          http://s807.photobucket.com/user/budm/library/

                          TV Factory reset codes listing:
                          http://www.badcaps.net/forum/showthread.php?t=24809

                          Comment


                            #14
                            Re: Power adapter from Apple Time Capsule - 0V at output

                            Originally posted by budm View Post
                            Since you will be working in the primary (HOT) side of the circuit, make sure to plug this board into the Isolation transformer before attaching your scope probes to the board.
                            Trying the IC will be a good idea.
                            Can you please explain what is isolation transformer?

                            Comment


                              #15
                              Re: Power adapter from Apple Time Capsule - 0V at output

                              http://www.hammondmfg.com/171.htm
                              You need to isolate what you are working on from primary power.
                              Last edited by budm; 03-03-2014, 04:21 PM.
                              Never stop learning
                              Basic LCD TV and Monitor troubleshooting guides.
                              http://www.badcaps.net/forum/showthr...956#post305956

                              Voltage Regulator (LDO) testing:
                              http://www.badcaps.net/forum/showthr...999#post300999

                              Inverter testing using old CFL:
                              http://www.badcaps.net/forum/showthr...er+testing+cfl

                              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                              http://s807.photobucket.com/user/budm/library/

                              TV Factory reset codes listing:
                              http://www.badcaps.net/forum/showthread.php?t=24809

                              Comment


                                #16
                                Re: Power adapter from Apple Time Capsule - 0V at output

                                What the actual fuck, Apple charge how much for their time capsules and you don't even get half decent caps? What a joke.
                                Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                Comment


                                  #17
                                  Re: Power adapter from Apple Time Capsule - 0V at output

                                  Originally posted by tom66 View Post
                                  What the actual fuck, Apple charge how much for their time capsules and you don't even get half decent caps? What a joke.
                                  I have not understand what you want to tell, I think you joke about big caps? I just soldered what I found at market, for testing, when I'll found the problem and PSU will work, I'll found more compact caps.

                                  Comment


                                    #18
                                    Re: Power adapter from Apple Time Capsule - 0V at output

                                    Originally posted by andrey_ka View Post
                                    I have not understand what you want to tell, I think you joke about big caps? I just soldered what I found at market, for testing, when I'll found the problem and PSU will work, I'll found more compact caps.
                                    It's not that they're big, it's that CapXon is one of the worst brands of capacitors in the world.

                                    Comment


                                      #19
                                      Re: Power adapter from Apple Time Capsule - 0V at output

                                      Originally posted by cheapie View Post
                                      It's not that they're big, it's that CapXon is one of the worst brands of capacitors in the world.
                                      Ok, but we don't have other (only "Chang" but I think it even worster china brand)

                                      if this project will work, I'll order something via eBay!

                                      Comment


                                        #20
                                        Re: Power adapter from Apple Time Capsule - 0V at output

                                        Originally posted by andrey_ka View Post
                                        I have not understand what you want to tell, I think you joke about big caps? I just soldered what I found at market, for testing, when I'll found the problem and PSU will work, I'll found more compact caps.
                                        No, I mean Apple use CapXon capacitors which are terrible. I have no complaint with yourself -- sorry if it came across a little harsh, I'm just disappointed that a company which is well known for charging large amounts for what essentially amounts to shinier products than other companies, cannot at least put in good components.
                                        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                        Comment

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