For those who want to save a couple bucks and avoid a drive to Walmart, go to Radio Shack and buy the following: 1. Part 273-348 adaptaplug power cord 2. Part 273-324 adaptaplug G 3. Part 273-335 adaptaplug B ($24 total) Assemble the cable by inserting both tips with the same polarity - with the tip letter and the 'negative' or 'minus' aligned with the label on the power cord that says 'TIP'. This preserves the polarity of the XP18000, which is what the EP121 requires (negative on the outside of the pin, positive on the inside). This will work. I am using it now. It is silly that Xpal takes months to figure this out. They should reimburse owners for the Radio Shack purchase.