The ps5 had a seriously ripped fan connector. The pads were completely gone. I had to use 0.1mm enamel opper wire so I can point to point wire the signal pin to the PCB.
The issue is when there’s no fan connected I get a nice pwm signal on my scope. But when I plug a supposedly brand new fan, the signal disappears.
Why?
Are the 12V present at the connector if the fan is plugged in?
Yes it’s there. Thats why am confused.
I have ordered a new fan from ifixit but the replacement fan doesn’t spin either. I have both pwm signal and 12v power. But still no fan spin. why?
what diode reading on the pwm pin from fan connector?
I got 0.787 between the pwm pin and gnd. I must say i had to repair the fan connector. It was very badly ripped. I had to run a wire from the pwm pin to the alternative pad on the back of the motherboard. But the console switches on,no magic smoke and pwm signal is there so I presume I was successful?
i am interested in knowing why the diode reading is relavent
Thanks alot for everyone’s help. I have put the connector upside down so the power and pwm pins were reversed. Looool. It took me hours to realise this.
You found the issue. 
It sounds a bit like me: soldering a SSD controller 90° rotated due to misstake the bigger round part for the pin 1 marking. 