How fans stopped working is.. 12V goes from the molex through the leftmost red/black to the PCB.
Said PCB has led control switch attached to it. (red/off/blue) and also has the fan connected to it.
switch wont change how fan works at all, the current just goes through the PCB.
no current to PCB, no current to fan, fan wont turn.
The "to fix" directions can go two ways. either cut the red/black going to fan and reattach it to molex connector or attach molex connector to original red/black and get both leds and fans to work.
As long as you connect said red/black wires back to psu, the led's and fans should work.
both seem to go through the green PCB you point your finger at.
Thus if you manage to reconnect the black/red wires you cut to molex (red to yellow, black to black) for 12V input, it should all work.
the choices are:
1. take apart and fix current molex connector the wires were attached to and reattach it to new PSU. (taking molex connectors apart without correct tool to take out the pins is hard)
2. get new molex connector from molex to sata adapter and reuse that.
3. get new fans. (possibly easiest and cheapest way)
http://www.amazon.com/Brand-120mm-Cooling-Computer-Appliances/dp/B00N4HNBH0/ref=sr_1_16?s=pc&ie=UTF8&qid=1464537257&sr=1-16&refinements=p_36%3A1253503011%2Cp_72%3A1248879011
for choices 2 and 3, you should most likely compare price tags and go from there.
As side note, I'm still adamant in my belief that the original connector would have been disconnectable from PSU without cutting wires.