Update (2020):

Much of the content on this page was unfortunately lost during the migration from squarespace to wordpress. If you found this page and have any questions feel free to reach out and I’ll do my best to answer.

UPDATE (Jan ‘16):

It’s now almost a year later. I’ve used the boombox at the NYC Marathon (read about this here) and many other events and my modification to the plug worked perfectly.


This power supply came with a TDK boombox I got for my birthday a few years back and just recently stopped working. I did a little searching for a replacement charger but found nothing, and because of the weird voltage and amperage (18v, 1666mA) a generic one would have been hard to find. I decided to investigate.

The power supply in question.


The culprit: Due to strain on the cable over time at the point where it enters the power supply, the internal wiring became frayed and disconnected. The same thing happened on my macbook (on the plug end that time) so I pretty much knew what had happened when I saw this bulge in the cable.


Taking apart the PSU was harder than I had anticipated. I ended up having to use my dremel tool and a plastic cutting wheel to cut around the perimeter of the plastic housing, where it had been sealed together at the factory. Lots of black plastic dust not shown. I was surprised with how densely packed in the electronics were inside the charger.


After taking it apart I decided to do a little upgrade and lengthen the wire using this generic two pin cable that I cut off of a broken TV that was in the garbage. I then cut the wires that originally went to the wall plug connector on the inside of the PSU and stripped them.


Interestingly, both this cable and the aforementioned macbook cable use a similar design for the power cord. The positive terminal is surrounded by the negative terminal as shown in the cutaway view to the right. I guess this type of cable is not ideal for situations where there is a lot of repeated bending on the wire in the same spot.


I stripped the wire by removing the outer rubber cover, then pulling the negative terminal out of the way and stripping the positive terminal. After it was stripped I twisted and electrical taped it to the wires coming off of the power supply.


I used a stack of mini post-its to isolate the two sides of the AC cable while I tested it to make sure it worked.


Next I made the necessary modifications to the case of the PSU. This included snipping off the AC prongs and using the dremel to cut out a place for the new AC power cable to enter the case.


I taped and zip tied the case back together and then used some more zip ties to route the wires coming out of the boombox around the PSU itself and secure them. I made loops in the cables on both sides so that if they were ever pulled the tension would be transferred to the zip ties instead of the solder points on the PSU pcb.


Success! The boombox is alive again and the power plug is now no longer a wall-wart and twice as long.