CPU & PSU fan not working

Hello,
I have recently bought my PC and built it last week. everything was running smooth till today, upon turning the PC i heard beeping from my motherboard and a message on my monitor telling me that the CPU fan has an error. So i open the case and find the CPU and PSU fans spin for a second then stop for about three seconds and then spins again and so on.I can still use the PC but stopped just in case anything worse happens.

So far I think the PSU is faulty but not sure.

My build:
ASUS SABERTOOTH Z77 (mobo)
i7 3770k (CPU + Stock fan)
CORSAIR GS800 (PSU)
GIGABYTE GTX 660ti windforce (GPU)
SAMSUNG 830 128GB (SSD)
Seagate 7200.12 1TB (HDD)