No power at all on PS4

Hi,

I have a PS4 Slim CUH 2216. There is no power at all. I have replaced the power supply unit. Nothing. I tested the previous unit and am getting 12v and 5v from the connectors off of the power suplly unit (even the old one) so know its not that. I was going to try replacing the power management chip but can't find one to buy anywhere. Assuming its not the APU as there is no power at all. I have rework station, solder iron multi meter microscope etc and am fairly confident working on it, just can't figure out what the issue is!

Many thanks,

Ben.