[SOLVED]820-3115 no hdd detect

[MDY]

Is there any common problem with these boards? I have severals and no one detect the hdd.I checked =PP5V_S0_HDD and it jumped from 5V to 3V
Of course I replaced hdd and cable already.

 

[MDY]

Ok, found bad coil but cannot understand why they got bad is hdd and cable is ok.