ATX Power Supply Dual +12 V Outputs: Fakery Thereof

I wondered if the Thing-O-Matic would benefit from having its two high-current heaters on a separate +12 V supply than the DC Extruder, after finding that the heaters dragged the +12 V output down by nearly half a volt.

A bit of rummaging turned up a suitable ATX supply with a data plate that might justifiably lead one to believe that the supply provides separate +12 V outputs:

Turbolink ATX-CW420W power supply data plate
Turbolink ATX-CW420W power supply data plate

There’s no indication which of the four connectors might use +12V1 and +12V2, but, being that sort of guy, I applied an ohmmeter to the various yellow wires and found they were all exactly 0.0 Ω apart.


So I opened the Warranty Void If Seal Removed top cover and found this situation:

ATX with fake dual 12 V supplies
ATX with fake dual 12 V supplies

Nota bene:

  • All the yellow wires terminate in the same solder blob below the PCB
  • Two incoming wires got neatly spliced together in mid-air, despite having free holes in the PCB

This may not come as much of a shock: they lie…

Perhaps if you spend more money on your supply, it’ll actually live up to the data plate specs. Then, again, perhaps you’ll just be spending more money.

And, if you swap in a fancy supply for the MBI-stock one, it might not make much difference at all. I suspect the various power levels and current capacities have pretty much the same degree of integrity…