Got a old PC computer laying around. Pull that power supply out of it. They have 12 volts and between 2 and 5 amps rating.
Just what Flex 1500 needs.
The power supply has lots of wires the ones that have the four wires is what were working on.
Find two such assemblies come out of the power supply. Cut the four pin plugs off all the wire from these two harness. We going to use the yellow wires they have 12 volts DC positive we need two of them to carry the voltage and amps.
Next tape back the red wires were not going to use them . (Note) these red wires are about 6 volts dc.
The back wire you probably have four of them if so tape back two of them were only going to use two them . This is your negative wires
Need to install a low amp fuse . You can buy the holder at a Auto Parts store fuse should be 1 to 3 amps. Install this on red wires.
Now we have power supply black is ground , red wire plus 12 volts.
Now that big plug with all the wire on it , find the only green wire next a black wire the closes to the green wire. Find a paper clip cut off a section of it bend it and install in the green and black wire. You can install a piece of electrical tape over the paper clip.
plug in the 110 volt cord and test the back and red wire should 12 volts.
You just saved yourself about $40.00 to $50.00.
I have my supply the fan end pointed at the side of the Flex 1500 this keeps the Flex very cool the touch.