Apple iPod HI-FI Dock A1121 (M9867ZH/A)

If you are here, you probably know what the Apple iPod HIFI Dock / Speaker is: the single rare and discontinued Apple speakers dock, which still presents high interest for the enthusiasts.

Identification

  • Part No: M9867ZH/A
  • Model No: A1121

Apple iPod HI-FI Dock Internal Design

How to Open Apple iPod HI-FI Dock

Before reaching to any screw on this product, you have to unglue the front black aluminium panel (the one you see after taking the grill off). A layer of glue is used on the whole surface of this 1-2mm thick aluminium panel, which makes this product one of the worst repairable.

Taking this step should be done with high caution as it can lead to damaged speakers or bent front plate. The easiest method I found is to preheat the front plate gradually with a hair-dryer, as you advance with a cutter between the front aluminium plate and the underside baffle, putting constant tension on the aluminium plate to help prying the glue. This is a two persons recomended job, as you have to hold the heater, apply tension to the plate and pry with a cutter or knife at the same time, all in a good lighted environment. Pay very close attention to where your cutter blade reaches, as there is a very high chance to get it into the exposed speakers rubber surround suspension !!!

Inside the Apple iPod HI-FI Dock

Apple iPod HI-FI Dock Troubleshooting Service Instructions

Apple iPod HI-FI Dock Troubleshooting Service Instructions

 

Apple iPod HI-FI Dock Power Supply

Power supply is Lite-On PA-3150-01A and provides a total combined DC output of 30W.

The power supply assembly is providing required voltages for the amplifier and charging docking board, but also signalling low battery and good battery when running on batteries.

Apple iPod HI-FI Dock Power Supply Components and Repair Tips

Stay tuned for more photos !

Leaking capacitors – common main fault of Apple iPod HI-FI Dock failure

The big 450v/100 uF capacitors used inside the power supply are manufactured by TAICON. TAICON brand is the short name for Taiwan Capacitor Ltd, which was established in 1969 in Taipei, Taiwan by Nichicon Japan, as a joint venture, for production of aluminum electrolytic capacitor. The relation with Nichicon sounds like a good thing, but there is a big amount of reports of failed Taicon capacitors in brand computers like Dell, and various motherbards. for production of aluminum electrolytic capacitor. Word is that Taicon was also behind the defective Nichicon HN and HM series.

In my conclusion, they should be considered the low-cost Nichicon, but definitely no warranty of sustained quality or high quality expectations, especially when used in high temperature conditions (like the closed, no cooling enclosure of the iPod HI-FI dock PSU).

Proof of the low quality of these capacitors is that in most cases on this device, they leaked from bottom, instead of venting on the top. This also causes corrosion to the printed circuit board, and helps bonding carbon connections between close spots under them. There is one spot on this PCB where you have to thoroughly clean the board, because the copper of the positive and negative are close enough to short-circuit when aided by this fault.

Symptomps of leaked capacitors on the iPod HIFI dock:

  • no power at all (burned/melted thermal fuse and/or thermistor)
  • not running on batteries either, as reported by other cases

Other effects of leaked capacitors:

  • pcb contamination
  • rotted cable cushion/damping foam
  • contamination of other components as an effect of the blowing fuse

Power Supply Thermistor

Inline with the input power cord is a NTC power thermistor, part number SCK10-2R55A. It has 2.5 ohm resistance at 25’C and can handle a 5A current. It’s main role is to aid gradual charging of the four big capacitors.  SCK10-2R55A Datasheet

SCK10-2R55A Datasheet

Power Supply Bridge Rectifier

Bridge rectifier is KBP-206, which can handle 2A.

Apple iPod HI-FI Dock Power Supply Connectors Pinout

Pin Nr. Wire colour Signal Value range
Gray Amplifier voltage + 17V 1.6A (0.5A on DC input)
+3.3V  0.1A
+6V  0.3A
Violet Low Battery
Brown Battery Good
Black Ground
Black/White RTN
Black DC INPUT BATT+ 7.5~9.9V 5A
Black DC INPUT BATT-

Apple iPod HI-FI Dock charging iPod circuit mods/enhancements

The charging specification is 12V FireWire charging, unlike the 5V USB specified in 2008, so newer devices like the iPhone/iPod nano 4th/iPod touch 2nd can not be charged.

Solutions to these issue can be found here:

Apple iPod HI-FI Dock clones and look alike

1. DENVER IPOD DOCK STATION SPEAKER SYSTEM BOX 2.1

Denver iPod Dock Station – eBay

Sources and references

  • I have a problem.
    The device to connect the phone, generates strange sounds. (transformers?)

  • Frannie

    Thank you for this brilliant round up. One questions stays.. Where did you get the SCK10-2R55A from? I can´t get it from any shop in the internet.

    Thanks a lot.

    Frannie

    • Tech

      If you can’t find the SCK10-2R55A which is manufactured by Meritek, you can check the datasheet (you have a link in the article) and look for a compatible NTC POWER THERMISTOR having the same main characteristics:
      SCK10-2R55A:
      – Zero Power Resistance at 25’C = 2.5 ohm
      – Max. Steady State Current at 25’C = 5A
      – Approx. Resistance at Max.Current at 25’C = 120 ohm
      – Thermal Dissipation Constant = 18 mw/’C
      – Thermal time constant = 46 sec
      – Operating temperature = -40 .. +170 ‘C

      • DJ

        I found one with similar characteristics: EPCOS B57236S259M
        http://www.farnell.com/datasheets/85723.pdf

        I’m not sure whether the 5.5A max. steady state current will be a problem. This is the closest I can find in my country. There is an alternative available rated for 5A but its resistance is 5ohm (double that of the original component): EPCOS B57237S509M. Any thoughts on this?

        Also, if the thermistor has blown, do you recommend replacing any other components? Some of the large capacitors and surrounding components are covered in a carbon residue (the same as your image with the black residue on the yellow component). My guessing is that the caps overheated due to the thermistor shattering, but I don’t know if this residue is the result of burning or leaking, or if it’s normal.

        Could really do with your expertise on this. I can take pictures if needs be.

        • Tech

          I would choose the 5.5A Max. Steady State Current at 25′C, as it is close to 5A and slightly higher current rating can’t do harm, and stay as close to the Zero Power Resistance at 25′C at 2.5 ohm.
          If the thermistor is blown, almost for sure the cause of it are the big capacitors. Check if they leaked underneath by removing one of them. Also a sign of leaked capacitors would be checking the foam around the internal cables of the dock to see if it is slightly rotten and is disintegrating, leaving black soft spongy particles all over inside. My guess is the other way around: thermistor has blown because of bad caps. You can attach photos here if it’s handy.

          • wingerotw

            Thanks very much for getting back to me on this. I’ll go for the thermistor you’ve recommended. I’ve inspected further
            and there is definite leakage under at least one capacitor. Here are
            some photos I’ve taken: http://bit.ly/1uDY6mt

            It’s a little hard to see but the cap on the left
            leaked underneath. Also, the cap on the right has a cracked plastic cover, which I’ve never seen before. I’ll replace all four since you reckon they’re poor quality. Really hoping there hasn’t been some snowball effect of faulty components as a result of the leaking capacitors.

            I’ll get a new thermistor and 4 new caps. Is there anything else that was probably affected?

            DJ

  • Joe Stremplewski

    Where can I send my Hi-Fi for repairs? I’m in Chicago.

  • Bruce

    OK – So a thread awakens 🙂

    Mine did the thing, but prior to failing the battery operation had failed, pointing to Capacitor failure. Device shelved as I looked for a new PS or another approach. This article inspired me so 5 years on work began.

    I opened it to find degraded foam so pressed on. 4 new CAPS, a EPCOS B57236S259M MOV to replace the blown one and a new Bridge rectifier (not clear if that was broken or I blew it). Much board cleaning and scrubbing and it’s all up and working again.

    I chose to bridge out the on-board fuse which had also failed, in favor of installing one that can be accessed externally with the same characteristics, 3A Ceramic Slo-Blow because opening this thing up is REALLY hard. and its now working beautifully. Looks like even the battery option is working again.

    Thank you for this write up so well, and also for the links to some other key resources.

    Bruce – Sydney AU

  • Bruce

    A thread awakens 🙂

    Mine did the thing, but prior to failing the battery operation had failed, pointing to Capacitor failure. Device shelved as I looked for a new PS or another approach. This article inspired me so 5 years on work began.
    I opened it to find degraded foam so pressed on. 4 new CAPS, a EPCOS B57236S259M MOV to replace the blown one and a new Bridge rectifier (not clear if that was broken or I blew it). Much board cleaning and scrubbing and it’s all up and working again.

    I chose to bridge out the on-board fuse which had also failed, in favor of installing one that can be accessed externally with the same characteristics, 3A Ceramic Slo-Blow because opening this thing up is REALLY hard. and its now working beautifully. Looks like even the battery option is working again.

    Thank you for this write up so well, and also for the links to some other key resources.

    Bruce – Sydney AU

  • Bruce

    I am waking up this thread

    Mine did the thing, but prior to failing the battery operation had failed, pointing to Capacitor failure. Device shelved as I looked for a new PS or another approach. This article inspired me so 5 years on work began.
    I opened it to find degraded foam so pressed on. 4 new CAPS, a EPCOS B57236S259M MOV to replace the blown one and a new Bridge rectifier (not clear if that was broken or I blew it). Much board cleaning and scrubbing and it’s all up and working again.

    I chose to bridge out the on-board fuse which had also failed, in favor of installing one that can be accessed externally with the same characteristics, 3A Ceramic Slo-Blow because opening this thing up is REALLY hard. and its now working beautifully. Looks like even the battery option is working again.

    Thank you for this write up so well, and also for the links to some other key resources.

    Bruce – Sydney AU
    https://uploads.disquscdn.com/images/386d5d04f43c019ba25a889138f7af043b928b51d5cb641947f9bc6f9fa24b31.jpg https://uploads.disquscdn.com/images/62ec1eee7020b85d2ee308f449b38545ffb54c6c092dcafc1b9f755bdb76b101.jpg https://uploads.disquscdn.com/images/f26078169c26d86270c76c57a89f438f858f1f7efaa4ddb0f3c9fa12968d8779.jpg

    • Thanks for sharing Bruce, good idea with the external fuse. If just we can source a white coin slotted cap fuse holder to sit flush on the enclosure back, that would be so awesome and OEM looking! 🙂

    • Robin Keussen

      Hi Bruce, I have just stumbled across your post about fixing the Apple Hifi, I have the same issue and am wondering if you can help me out as I am also in Sydney.