Crest Smart Home Single Power Adaptor SHSPM1 (rebadged Tuya device) - bad cap causing failure, how to repair

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  • mrdevil
    Member
    • Apr 2008
    • 10

    #1

    Crest Smart Home Single Power Adaptor SHSPM1 (rebadged Tuya device) - bad cap causing failure, how to repair

    Hi all,

    Wanted to share this as I couldn't find anything on the internet about this problem, so pulled one apart and found the problem myself. Years ago I bought approx 20 or so Crest Smart Home Single Power Adapter smart switches - small 240v Tuya-compatible (rebranded) smart switch devices with power monitoring, which Big W had on sale for half price. Paid $7.50 each for these, and they've been incredibly useful for turning things on and off remotely... and monitoring how much power each device uses.

    However, after about 12 months, I had a number of these stop working - some would start buzzing and continually clicking on and off by themselves, others would just flat out die. When unplugged / plugged back in, they wouldn't respond - the blue LED to indicate they're on wouldn't illuminate... basically they appeared dead.

    First one to do this - thought it must be a dud. Second... then third... figured something was up, so pulled one apart, and found these have a 10V 470uf capacitor that bulges and fails. Replaced this, and it works just like a new one. Done this to about 7 or 8 so far... only had one where I replaced the capacitor and this didn't work, but couldn't be bothered investigating further as I already have devices spare.

    Item details - model # SHSPM1

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    Instructions with photos...

    Open the device up - unfortunately these appear to be clamped / welded shut, do so a bit of brute force is needed. I usually cut along the edges with a stanley knife, then tap a flathead screwdriver into the seams to pop them open. When putting back together, I cut off any plastic that sticks out / prevents them closing neatly, then put a couple of drops of superglue along the edges to secure them closed once working again.

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    Unscrew the PCB - I've noticed some of these have three screws, others only have two. Once you've removed these, you can pull the PCB away from the power plug prongs gently - the cable will feed through holes in the PCB... you should be able to separate these enough to do the soldering that's required.

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    Replace the dodgy capacitor - I've circled the dodgy one below. Should be a 10V 470uf capacitor.

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    Test - I'd normally them slip the outer shell back on, and plug the device in to test. If successful you should be able to turn the device on and off using the power button, with the blue LED illuminating when switched on.

    Reassemble - Unplug, remove the cover again, push the PCB back towards the plug - you may need to pull the cables out a bit to make this work. Screw the screws that secure the PCB back in, then put the protective cover back on. I usually secure this with a few drops of superglue to prevent it accidentally pulling off later on, given cracking the device open tends to break the clips / glue that hold this together.

    Hope someone may find this information useful at some point They're great / cheap devices... when they work of course.
  • mon2
    Badcaps Legend
    • Dec 2019
    • 13836
    • Canada

    #2
    Measure the dimensions and select a brand name replacement.

    The following should be suitable:

    https://www.mouser.com/ProductDetail...Pbq437VA%3D%3D

    Comment

    • stj
      Great Sage 齊天大聖
      • Dec 2009
      • 30931
      • Albion

      #3
      there is something suspicious about this.
      i would solder a couple of thin wires under the cap and meter the voltage while it's running - maybe it's under-rated.
      i would use a 16v part if it will fit and use a low impedence high temp part like a panasonic FR or a rubycon ZL incase it's a high frequency circuit.

      Comment

      • stj
        Great Sage 齊天大聖
        • Dec 2009
        • 30931
        • Albion

        #4
        interesting plug btw,
        is it Chinese, or Australian?

        Comment

        • mrdevil
          Member
          • Apr 2008
          • 10

          #5
          It's an Australian plug - I believe it's similar to some that are found in China, however ours require the live and neutral pins to be insulated part of the way. As for replacement parts, I just ordered a 20x pack of cheap capacitors from AliExpress for a few dollars. First one I repaired was about 6-8 months ago and its still working fine - as are the ones I've repaired since.

          Comment

          • CapLeaker
            Leaking Member
            • Dec 2014
            • 7986
            • Canada

            #6
            Hmm… same idea as a “Shelly plug”. Had other fails like cracked solder joints or ripped screw terminals on the Shelly plus 1, but all of them are still working.

            Comment

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