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Squeezebox Controller (remote) cradle/charger PSU issue: controller boot loop

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  • Squeezebox Controller (remote) cradle/charger PSU issue: controller boot loop

    Here's another power supply electrolytics story. I watched in horror this morning as my Squeezebox Controller gave a light show of button backlight, showing the logo briefly on the LCD, then rebooting.
    At first I thought that the Controller is on its way out for no good reason, or its battery. Checked a lot of things inside and out but nothing really helped. Trying a different battery didn't really help but that was probably because the second battery was also discharged.
    Then I had the idea that the power supply for the Controller's charging cradle is similar to the SB3 classic one that fails ever so often and makes it appear like the SB3 itself is at fault while it's just the PSU.
    If the cradle PSU fails, it is no longer capable of powering the Controller, and the Controller won't get to charge the battery long enough for anything to finish correctly.
    So I hacked the PSU case open with a hammer and spudger because it is ultrasonically sealed like all of them and can't be opened without a lot of violence. This is what I found inside:

    Click image for larger version

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    For perspective, this is what you see when the mains adaptor was removed. The high voltage side where the adaptor connects is facing down in this photo.
    The two capacitors indicated are heavily bulged and the one on the left had also started leaking. Luckily, only at the top that was designed to let pressure escape, not at the bottom, so the PCB was unharmed. Replaced these two capacitors (680µF / 10V) by new ones and the power supply was completely dead. Oh my...
    So I checked around and did a close visual inspection. Turns out my opening procedure had me whack a choke and severed two or three of the tiny wires from the legs of the component. This is the one I mean:

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    Let's remember for next time that we should be *very* careful around this corner. It was very fiddly to repair the choke after I damaged it, I needed to desolder it entirely, resolder the microscropic wires (with no room or length to spare) to the legs which had partly separated, and put the fixed component back in. All in close proximity to the capacitors holding a high voltage charge. But eventually that brought it back to life. The Controller charges again and starts up normally.
    The cradle PSU is a 5V / 2A one, probably identical to the SB3 stock power supply. So that one might be repairable just the same way.
    Eventually the plastic case needs to be closed again to ensure that none of the components can be touched accidentally. I put the two halves back together and used Kapton tape to go two times around the "waist" of the PSU.

    Some advice for you in case you want to DIY:
    • Dremel might at first look like a good idea to open the case, but be aware that components are very tightly packed inside the PSU, and are also close to the outer shell, so you may accidentally grind into one of them. Also, using anything that grinds away the seal will cause material to be missing once the time comes to reassemble
    • again, be especially careful in the corner indicated above, but also be aware that there are components almost all around that could be nicked or heavily damaged if you go too far with whatever you drive into the seal to crack it open
    • the two larger capacitors on the primary side (flip-side to where the AC connection sits) are charged with up to 400 Volts, and as far as I could see, there is no discharge resistor so they will hold this voltage for a long time. Stay away from these as far as possible, or safely discharge them before handling the board. I would assume that they will self-discharge in about 12 hours after unplugging, but don't take my word for it. If a multimeter is in your collection, use it to measure the voltages in these caps
    • discharging is best done with specific equipment (best choice), or a high-value resistor (something like 1M Ohms, second-best choice) or an oldschool mains-voltage light bulb with a Tungsten filament (third-best choice) connected across the capacitor's pins. It is generally not recommended to just short out the capacitor legs because it may create a heavy arc and may also damage the capacitor or components around it in case anything else gets connected in the same instant
    • after discharging, ensure with a multimeter that the charge is actually gone and won't return
    • the two secondary capacitors were the only ones bad in my power supply. It may look differently in yours. Bulged or leaky capacitors should be replaced for good at all times. Replace them all if you want to be completely safe against future defects. The electrolytics are polarized, so you need to ensure to put the replacement caps in the same polarity as the originals were. A stripe along one side indicates the NEGATIVE terminal (usually the same color as the rating print). The silk screen print beneath the caps on the PCB indicates this negative terminal with some highlighting, and also shows a "+" symbol where the POSITIVE side needs to go
    • both secondary capacitors are in parallel (+ and - of both are joined) for double capacity
    • be sure to measure the PSU output before you put the Controller into its cradle. If anything looks off, voltage appears reversed, too high, or too low, DO NOT connect the Controller and fix the issue first
    • in case you plan to replace the PSU entirely, you will need to connect another one to the wire that goes to the cradle. The white wire is +5VDC and the black one is GND. Inside the cradle, the left spring is GND and the right one needs to be +5VDC.

    Attached Files

    PN me if your Boom / Classic / Transporter display has issues!


  • #2
    JoeMuc2009 You're not alone with the PS for the controller failing. Since it's a 5V PS I just spliced a USB-A cable to the Controller cable and use a phone charger for the PS, works great. If that fails just unplug and get a new phone charger. See this post.
    The one place to discuss the one Squeezebox to control them all... Squeezebox Duet, and Squeezebox Controller & Squeezebox Receiver too.

    Main system - Rock Solid with LMS 8.3.1 on WHS 2011 - 2 Duets ( both WiFi, farthest unit gets 60% signal strength and always works since new power supply) and Squeeseslave
    Cabin system - Rock solid with LMS 8.3.1 on Win10 Pro - 1 RPi 3 Model B (WiFi) /Hifiberry DAC+ Pro/PiCorePlayer and Squeezeslave
    Squeezebox Boom - "At Large" player around both home and cabin
    Headphones and car - Android phone/Bluetooth w/full library on MicroSD card - PowerAmp music player app (similar to Material Skin)


    • #3
      JoeMuc2009 you are a braver man than I, but thanks for the look inside and observations. Similar to w3w, I spliced in a new power supply, something I had laying around.



      • #4
        Written at length for first-timer failing-charger folk.

        There is a way to help determine if the PSU is beginning to fail, for those who aren't handy with a multimeter (or at fixing with a soldering iron). Stick the controller on the charger, battery in place, and turn it on. It will go through this endless loop, keys light up, Logitech logo appears, then it restarts. The charger output is insufficient to run the controller and charge the battery. Now, leaving the controller in the charger, turn the controller off, leaving it on charge for at least 24 hours. Then, take it out of the controller and turn it on. It's likely got charge enough to run for a while, probably/possibly showing as full battery. The battery will, however, not have full charge by any means. Play with the controller until the battery indicator has gone down by one blip (likely won't be long...) then put it back onto charge. In all likelihood, it will almost immediately flip back to indicating full charge, and will not go through the battery indicator flicking from 1/4,1/2, 3/4, full. It just jumps to full charge. (If left on the charger, it will eventually go back to flicking on to Logitech, and off again; the battery is discharging faster than the charger can charge it).

        The easiest fix is to bravely cut the cable down by the plug, and splice it into a USB cable. It's not difficult, soldering is best, but there are neat ways of splicing wires on YouTube. Leave as much cable on the charger end as possible, as it will give you lengths to fail on . Use a quality USB cable, ideally a thicker charging cable, as it'll be easier and better done that way. Do not use the thinnest old spare you find in the junk draw! Shrink-wrap electrical tubing is easy to use (hair dryer, even candle, cigarette lighter or match at a push). Use a 2 amp or more USB PSU and, if in doubt about your quality of work, only initially charge it when you are there, and check the wiring for any heating up.

        The charger's white wire is positive, black negative. USB red is positive, black negative. I think... Dump the other USB wires.

        A neater alternative that I have done is open the charging base (two screws under the label and then rubber base, peel back slowly and carefully), desolder the original wires from the PCB, extract the old wires from the thick rubber pad, and replace the whole thing with either USB or a replacement PSU, your choice. Reassemble. Use a quality PSU if doing this. It looks better, is probably marginally safer, and is actually very easy to do.

        Last edited by Benjh; 2023-09-07, 11:04.


        • #5
          Originally posted by Benjh

          A neater alternative that I have done is open the controller (two screws under the label and then rubber base, peel back slowly and carefully), desolder the original wires from the PCB, extract the old wires from the thick rubber pad, and replace the whole thing with either USB or a replacement PSU, your choice. Reassemble. Use a quality PSU if doing this. It looks better, is probably marginally safer, and is actually very easy to do.

          you mean charging base, not controller, right? I doubt anyone wants a cable hanging out of their controller



          • #6
            (I think you must have misread... I'm sure there's no edit function on this Forum... )

            Thanks, Jim. Hadn't noticed. Corrected.